21097139616 has 72 divisors (see below), whose sum is σ = 68565710304. Its totient is φ = 6027753600.

The previous prime is 21097139593. The next prime is 21097139633. The reversal of 21097139616 is 61693179012.

21097139616 is a `hidden beast` number, since 2 + 10 + 9 + 7 + 13 + 9 + 616 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

It is a super-3 number, since 3×21097139616³ (a number of 32 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5230410 + ... + 5234441.

It is an arithmetic number, because the mean of its divisors is an integer number (952301532).

Almost surely, 2^21097139616 is an apocalyptic number.

It is an amenable number.

21097139616 is an abundant number, since it is smaller than the sum of its proper divisors (47468570688).

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

21097139616 is a wasteful number, since it uses less digits than its factorization.

21097139616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10464874 (or 10464863 counting only the distinct ones).

The product of its (nonzero) digits is 122472, while the sum is 45.

The spelling of 21097139616 in words is "twenty-one billion, ninety-seven million, one hundred thirty-nine thousand, six hundred sixteen".