20399185278056 has 128 divisors (see below), whose sum is σ = 44984477260800. Its totient is φ = 8587935498240.

The previous prime is 20399185278019. The next prime is 20399185278061. The reversal of 20399185278056 is 65087258199302.

It is a super-2 number, since 2×20399185278056² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20399185277983 and 20399185278001.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11222216 + ... + 12912648.

It is an arithmetic number, because the mean of its divisors is an integer number (351441228600).

Almost surely, 2^{20399185278056} is an apocalyptic number.

20399185278056 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20399185278056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22492238630400).

20399185278056 is an abundant number, since it is smaller than the sum of its proper divisors (24585291982744).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20399185278056 is a wasteful number, since it uses less digits than its factorization.

20399185278056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1690699 (or 1690695 counting only the distinct ones).

The product of its (nonzero) digits is 65318400, while the sum is 65.

The spelling of 20399185278056 in words is "twenty trillion, three hundred ninety-nine billion, one hundred eighty-five million, two hundred seventy-eight thousand, fifty-six".