21307491902961 has 12 divisors (see below), whose sum is σ = 33575441786640. Its totient is φ = 12913631456280.

The previous prime is 21307491902953. The next prime is 21307491902971. The reversal of 21307491902961 is 16920919470312.

21307491902961 is a `hidden beast` number, since 2 + 1 + 3 + 0 + 7 + 491 + 90 + 2 + 9 + 61 = 666.

It is not a de Polignac number, because 21307491902961 - 2³ = 21307491902953 is a prime.

It is a super-2 number, since 2×21307491902961² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21307491902898 and 21307491902907.

It is not an unprimeable number, because it can be changed into a prime (21307491902971) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 107613595371 + ... + 107613595568.

It is an arithmetic number, because the mean of its divisors is an integer number (2797953482220).

Almost surely, 2^{21307491902961} is an apocalyptic number.

It is an amenable number.

21307491902961 is a deficient number, since it is larger than the sum of its proper divisors (12267949883679).

21307491902961 is a wasteful number, since it uses less digits than its factorization.

21307491902961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 215227190956 (or 215227190953 counting only the distinct ones).

The product of its (nonzero) digits is 1469664, while the sum is 54.

The spelling of 21307491902961 in words is "twenty-one trillion, three hundred seven billion, four hundred ninety-one million, nine hundred two thousand, nine hundred sixty-one".