21465544140 has 72 divisors (see below), whose sum is σ = 65756881008. Its totient is φ = 5667465600.

The previous prime is 21465544129. The next prime is 21465544147. The reversal of 21465544140 is 4144556412.

21465544140 is a `hidden beast` number, since 2 + 1 + 465 + 54 + 4 + 140 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 21465544095 and 21465544104.

It is not an unprimeable number, because it can be changed into a prime (21465544147) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 572182 + ... + 608541.

It is an arithmetic number, because the mean of its divisors is an integer number (913290014).

Almost surely, 2^21465544140 is an apocalyptic number.

21465544140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21465544140 is an abundant number, since it is smaller than the sum of its proper divisors (44291336868).

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

21465544140 is a wasteful number, since it uses less digits than its factorization.

21465544140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1180839 (or 1180834 counting only the distinct ones).

The product of its (nonzero) digits is 76800, while the sum is 36.

The spelling of 21465544140 in words is "twenty-one billion, four hundred sixty-five million, five hundred forty-four thousand, one hundred forty".