21541636155 has 32 divisors (see below), whose sum is σ = 37565127936. Its totient is φ = 10477332864.

The previous prime is 21541636141. The next prime is 21541636163. The reversal of 21541636155 is 55163614512.

It is not a de Polignac number, because 21541636155 - 2⁷ = 21541636027 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 649297 + ... + 681666.

It is an arithmetic number, because the mean of its divisors is an integer number (1173910248).

Almost surely, 2^21541636155 is an apocalyptic number.

21541636155 is a deficient number, since it is larger than the sum of its proper divisors (16023491781).

21541636155 is a wasteful number, since it uses less digits than its factorization.

21541636155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1331067.

The product of its digits is 108000, while the sum is 39.

The spelling of 21541636155 in words is "twenty-one billion, five hundred forty-one million, six hundred thirty-six thousand, one hundred fifty-five".