21013287155715 has 32 divisors (see below), whose sum is σ = 34706444138496. Its totient is φ = 10845371335680.

The previous prime is 21013287155699. The next prime is 21013287155717. The reversal of 21013287155715 is 51755178231012.

It is not a de Polignac number, because 21013287155715 - 2⁴ = 21013287155699 is a prime.

It is a super-2 number, since 2×21013287155715² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21013287155717) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 27342904 + ... + 28100906.

It is an arithmetic number, because the mean of its divisors is an integer number (1084576379328).

Almost surely, 2^{21013287155715} is an apocalyptic number.

21013287155715 is a deficient number, since it is larger than the sum of its proper divisors (13693156982781).

21013287155715 is a wasteful number, since it uses less digits than its factorization.

21013287155715 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 817659.

The product of its (nonzero) digits is 588000, while the sum is 48.

The spelling of 21013287155715 in words is "twenty-one trillion, thirteen billion, two hundred eighty-seven million, one hundred fifty-five thousand, seven hundred fifteen".