20651620653 has 16 divisors (see below), whose sum is σ = 30599472960. Its totient is φ = 13765731408.

The previous prime is 20651620643. The next prime is 20651620667. The reversal of 20651620653 is 35602615602.

It is a happy number.

20651620653 is a `hidden beast` number, since 20 + 6 + 5 + 1 + 620 + 6 + 5 + 3 = 666.

It is not a de Polignac number, because 20651620653 - 2⁹ = 20651620141 is a prime.

It is a super-2 number, since 2×20651620653² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20651620603) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 144951 + ... + 249627.

It is an arithmetic number, because the mean of its divisors is an integer number (1912467060).

Almost surely, 2^20651620653 is an apocalyptic number.

It is an amenable number.

20651620653 is a deficient number, since it is larger than the sum of its proper divisors (9947852307).

20651620653 is a wasteful number, since it uses less digits than its factorization.

20651620653 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 111993 (or 111987 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 36.

The spelling of 20651620653 in words is "twenty billion, six hundred fifty-one million, six hundred twenty thousand, six hundred fifty-three".