21513420970 has 32 divisors (see below), whose sum is σ = 39827336400. Its totient is φ = 8360879616.

The previous prime is 21513420953. The next prime is 21513420979. The reversal of 21513420970 is 7902431512.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 15831427329 + 5681993641 = 125823^2 + 75379^2 .

It is not an unprimeable number, because it can be changed into a prime (21513420979) 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, 221326 + ... + 303334.

Almost surely, 2^21513420970 is an apocalyptic number.

21513420970 is a deficient number, since it is larger than the sum of its proper divisors (18313915430).

21513420970 is a wasteful number, since it uses less digits than its factorization.

21513420970 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82762.

The product of its (nonzero) digits is 15120, while the sum is 34.

The spelling of 21513420970 in words is "twenty-one billion, five hundred thirteen million, four hundred twenty thousand, nine hundred seventy".