21134205155 has 32 divisors (see below), whose sum is σ = 31287168000. Its totient is φ = 13383925632.

The previous prime is 21134205151. The next prime is 21134205161. The reversal of 21134205155 is 55150243112.

It is not a de Polignac number, because 21134205155 - 2² = 21134205151 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is not an unprimeable number, because it can be changed into a prime (21134205151) 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, 429305 + ... + 475994.

It is an arithmetic number, because the mean of its divisors is an integer number (977724000).

Almost surely, 2^21134205155 is an apocalyptic number.

21134205155 is a deficient number, since it is larger than the sum of its proper divisors (10152962845).

21134205155 is a wasteful number, since it uses less digits than its factorization.

21134205155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 905363.

The product of its (nonzero) digits is 6000, while the sum is 29.

Adding to 21134205155 its reverse (55150243112), we get a palindrome (76284448267).

The spelling of 21134205155 in words is "twenty-one billion, one hundred thirty-four million, two hundred five thousand, one hundred fifty-five".