21660671151 has 12 divisors (see below), whose sum is σ = 35757298512. Its totient is φ = 12377526336.

The previous prime is 21660671117. The next prime is 21660671161. The reversal of 21660671151 is 15117606612.

It is a happy number.

It is not a de Polignac number, because 21660671151 - 2¹¹ = 21660669103 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21660671111) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 171910026 + ... + 171910151.

It is an arithmetic number, because the mean of its divisors is an integer number (2979774876).

Almost surely, 2^21660671151 is an apocalyptic number.

21660671151 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21660671151 is a deficient number, since it is larger than the sum of its proper divisors (14096627361).

21660671151 is a wasteful number, since it uses less digits than its factorization.

21660671151 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 343820190 (or 343820187 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 36.

The spelling of 21660671151 in words is "twenty-one billion, six hundred sixty million, six hundred seventy-one thousand, one hundred fifty-one".