21154172151 has 24 divisors (see below), whose sum is σ = 32816824320. Its totient is φ = 12085787952.

The previous prime is 21154172141. The next prime is 21154172159. The reversal of 21154172151 is 15127145112.

It is not a de Polignac number, because 21154172151 - 2⁶ = 21154172087 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21154172159) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1022730 + ... + 1043208.

It is an arithmetic number, because the mean of its divisors is an integer number (1367367680).

Almost surely, 2^21154172151 is an apocalyptic number.

21154172151 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21154172151 is a deficient number, since it is larger than the sum of its proper divisors (11662652169).

21154172151 is a wasteful number, since it uses less digits than its factorization.

21154172151 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27523 (or 27516 counting only the distinct ones).

The product of its digits is 2800, while the sum is 30.

The spelling of 21154172151 in words is "twenty-one billion, one hundred fifty-four million, one hundred seventy-two thousand, one hundred fifty-one".