21357066056265 has 24 divisors (see below), whose sum is σ = 37019138836680. Its totient is φ = 11390366202624.

The previous prime is 21357066056231. The next prime is 21357066056303. The reversal of 21357066056265 is 56265066075312.

21357066056265 is a `hidden beast` number, since 2 + 1 + 3 + 5 + 7 + 0 + 6 + 6 + 0 + 5 + 626 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 13000272036921 + 8356794019344 = 3605589^2 + 2890812^2 .

It is not a de Polignac number, because 21357066056265 - 2¹² = 21357066052169 is a prime.

It is a super-2 number, since 2×21357066056265² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6558691 + ... + 9259079.

It is an arithmetic number, because the mean of its divisors is an integer number (1542464118195).

Almost surely, 2^{21357066056265} is an apocalyptic number.

It is an amenable number.

21357066056265 is a deficient number, since it is larger than the sum of its proper divisors (15662072780415).

21357066056265 is a wasteful number, since it uses less digits than its factorization.

21357066056265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2876153 (or 2876150 counting only the distinct ones).

The product of its (nonzero) digits is 13608000, while the sum is 54.

The spelling of 21357066056265 in words is "twenty-one trillion, three hundred fifty-seven billion, sixty-six million, fifty-six thousand, two hundred sixty-five".