21508022151 has 64 divisors (see below), whose sum is σ = 40205168640. Its totient is φ = 11038295520.

The previous prime is 21508022149. The next prime is 21508022153. The reversal of 21508022151 is 15122080512.

It is a happy number.

21508022151 is a `hidden beast` number, since 2 + 1 + 508 + 0 + 2 + 2 + 151 = 666.

It is an interprime number because it is at equal distance from previous prime (21508022149) and next prime (21508022153).

It is not a de Polignac number, because 21508022151 - 2¹ = 21508022149 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21508022153) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 110236 + ... + 234878.

It is an arithmetic number, because the mean of its divisors is an integer number (628205760).

Almost surely, 2^21508022151 is an apocalyptic number.

21508022151 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21508022151 is a deficient number, since it is larger than the sum of its proper divisors (18697146489).

21508022151 is a wasteful number, since it uses less digits than its factorization.

21508022151 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124753 (or 124747 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 27.

The spelling of 21508022151 in words is "twenty-one billion, five hundred eight million, twenty-two thousand, one hundred fifty-one".