21354212155 has 16 divisors (see below), whose sum is σ = 26246642400. Its totient is φ = 16669755648.

The previous prime is 21354212129. The next prime is 21354212179. The reversal of 21354212155 is 55121245312.

It is not a de Polignac number, because 21354212155 - 2⁵ = 21354212123 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 174021 + ... + 270169.

It is an arithmetic number, because the mean of its divisors is an integer number (1640415150).

Almost surely, 2^21354212155 is an apocalyptic number.

21354212155 is a deficient number, since it is larger than the sum of its proper divisors (4892430245).

21354212155 is a wasteful number, since it uses less digits than its factorization.

21354212155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97230.

The product of its digits is 12000, while the sum is 31.

Adding to 21354212155 its reverse (55121245312), we get a palindrome (76475457467).

The spelling of 21354212155 in words is "twenty-one billion, three hundred fifty-four million, two hundred twelve thousand, one hundred fifty-five".