21615263336541 has 32 divisors (see below), whose sum is σ = 33866059122688. Its totient is φ = 12004142068800.

The previous prime is 21615263336539. The next prime is 21615263336549. The reversal of 21615263336541 is 14563336251612.

It is not a de Polignac number, because 21615263336541 - 2¹ = 21615263336539 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21615263336549) 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, 15066385 + ... + 16438566.

It is an arithmetic number, because the mean of its divisors is an integer number (1058314347584).

Almost surely, 2^{21615263336541} is an apocalyptic number.

21615263336541 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21615263336541 is a deficient number, since it is larger than the sum of its proper divisors (12250795786147).

21615263336541 is a wasteful number, since it uses less digits than its factorization.

21615263336541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31505881.

The product of its digits is 2332800, while the sum is 48.

The spelling of 21615263336541 in words is "twenty-one trillion, six hundred fifteen billion, two hundred sixty-three million, three hundred thirty-six thousand, five hundred forty-one".