21087590637995 has 16 divisors (see below), whose sum is σ = 29327450001408. Its totient is φ = 14256399302880.

The previous prime is 21087590637991. The next prime is 21087590638001. The reversal of 21087590637995 is 59973609578012.

It is not a de Polignac number, because 21087590637995 - 2² = 21087590637991 is a prime.

It is a super-2 number, since 2×21087590637995² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (71).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21087590637991) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4242973499 + ... + 4242978468.

It is an arithmetic number, because the mean of its divisors is an integer number (1832965625088).

Almost surely, 2^{21087590637995} is an apocalyptic number.

21087590637995 is a deficient number, since it is larger than the sum of its proper divisors (8239859363413).

21087590637995 is an equidigital number, since it uses as much as digits as its factorization.

21087590637995 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8485952050.

The product of its (nonzero) digits is 257191200, while the sum is 71.

The spelling of 21087590637995 in words is "twenty-one trillion, eighty-seven billion, five hundred ninety million, six hundred thirty-seven thousand, nine hundred ninety-five".