21656246139 has 24 divisors (see below), whose sum is σ = 34130304000. Its totient is φ = 13122955440.

The previous prime is 21656246123. The next prime is 21656246141. The reversal of 21656246139 is 93164265612.

21656246139 is a `hidden beast` number, since 2 + 1 + 6 + 5 + 6 + 24 + 613 + 9 = 666.

It is not a de Polignac number, because 21656246139 - 2⁴ = 21656246123 is a prime.

It is a super-3 number, since 3×21656246139³ (a number of 32 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21656246094 and 21656246103.

It is not an unprimeable number, because it can be changed into a prime (21656246119) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 838582 + ... + 864020.

It is an arithmetic number, because the mean of its divisors is an integer number (1422096000).

Almost surely, 2^21656246139 is an apocalyptic number.

21656246139 is a deficient number, since it is larger than the sum of its proper divisors (12474057861).

21656246139 is a wasteful number, since it uses less digits than its factorization.

21656246139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34055 (or 34052 counting only the distinct ones).

The product of its digits is 466560, while the sum is 45.

The spelling of 21656246139 in words is "twenty-one billion, six hundred fifty-six million, two hundred forty-six thousand, one hundred thirty-nine".