21120165464640 has 224 divisors, whose sum is σ = 76333120644096. Its totient is φ = 4897429616640.

The previous prime is 21120165464633. The next prime is 21120165464641. The reversal of 21120165464640 is 4646456102112.

It is a happy number.

It is a super-2 number, since 2×21120165464640² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21120165464592 and 21120165464601.

It is not an unprimeable number, because it can be changed into a prime (21120165464641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 43235722 + ... + 43721481.

Almost surely, 2^{21120165464640} is an apocalyptic number.

21120165464640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21120165464640 is an abundant number, since it is smaller than the sum of its proper divisors (55212955179456).

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

21120165464640 is a wasteful number, since it uses less digits than its factorization.

21120165464640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86957257 (or 86957247 counting only the distinct ones).

The product of its (nonzero) digits is 276480, while the sum is 42.

The spelling of 21120165464640 in words is "twenty-one trillion, one hundred twenty billion, one hundred sixty-five million, four hundred sixty-four thousand, six hundred forty".