21086357651597 has 4 divisors (see below), whose sum is σ = 24098694458976. Its totient is φ = 18074020844220.

The previous prime is 21086357651537. The next prime is 21086357651599. The reversal of 21086357651597 is 79515675368012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21086357651597 - 2⁶ = 21086357651533 is a prime.

It is a super-2 number, since 2×21086357651597² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21086357651599) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1506168403679 + ... + 1506168403692.

It is an arithmetic number, because the mean of its divisors is an integer number (6024673614744).

Almost surely, 2^{21086357651597} is an apocalyptic number.

It is an amenable number.

21086357651597 is a deficient number, since it is larger than the sum of its proper divisors (3012336807379).

21086357651597 is an equidigital number, since it uses as much as digits as its factorization.

21086357651597 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3012336807378.

The product of its (nonzero) digits is 95256000, while the sum is 65.

The spelling of 21086357651597 in words is "twenty-one trillion, eighty-six billion, three hundred fifty-seven million, six hundred fifty-one thousand, five hundred ninety-seven".