21261162126515 has 16 divisors (see below), whose sum is σ = 26978758684416. Its totient is φ = 16058784921600.

The previous prime is 21261162126481. The next prime is 21261162126541. The reversal of 21261162126515 is 51562126116212.

It is not a de Polignac number, because 21261162126515 - 2²⁰ = 21261161077939 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1672783742 + ... + 1672796451.

It is an arithmetic number, because the mean of its divisors is an integer number (1686172417776).

Almost surely, 2^{21261162126515} is an apocalyptic number.

21261162126515 is a deficient number, since it is larger than the sum of its proper divisors (5717596557901).

21261162126515 is a wasteful number, since it uses less digits than its factorization.

21261162126515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3345580270.

The product of its digits is 86400, while the sum is 41.

The spelling of 21261162126515 in words is "twenty-one trillion, two hundred sixty-one billion, one hundred sixty-two million, one hundred twenty-six thousand, five hundred fifteen".