21952615680 has 144 divisors (see below), whose sum is σ = 77901418560. Its totient is φ = 5854021632.

The previous prime is 21952615649. The next prime is 21952615681. The reversal of 21952615680 is 8651625912.

21952615680 is a `hidden beast` number, since 21 + 9 + 5 + 2 + 61 + 568 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21952615681) 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, 283042 + ... + 352161.

Almost surely, 2^21952615680 is an apocalyptic number.

21952615680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21952615680 is an abundant number, since it is smaller than the sum of its proper divisors (55948802880).

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

21952615680 is an equidigital number, since it uses as much as digits as its factorization.

21952615680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 635233 (or 635213 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 45.

The spelling of 21952615680 in words is "twenty-one billion, nine hundred fifty-two million, six hundred fifteen thousand, six hundred eighty".