21151323146655 has 112 divisors (see below), whose sum is σ = 43393002730560. Its totient is φ = 9800431709184.

The previous prime is 21151323146651. The next prime is 21151323146659. The reversal of 21151323146655 is 55664132315112.

It is a happy number.

21151323146655 is a `hidden beast` number, since 2 + 1 + 1 + 5 + 132 + 3 + 1 + 466 + 55 = 666.

It is an interprime number because it is at equal distance from previous prime (21151323146651) and next prime (21151323146659).

It is not a de Polignac number, because 21151323146655 - 2² = 21151323146651 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 21151323146655.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21151323146651) by changing a digit.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 12323035 + ... + 13934124.

It is an arithmetic number, because the mean of its divisors is an integer number (387437524380).

Almost surely, 2^{21151323146655} is an apocalyptic number.

21151323146655 is an abundant number, since it is smaller than the sum of its proper divisors (22241679583905).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21151323146655 is a wasteful number, since it uses less digits than its factorization.

21151323146655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26257212 (or 26257197 counting only the distinct ones).

The product of its digits is 648000, while the sum is 45.

The spelling of 21151323146655 in words is "twenty-one trillion, one hundred fifty-one billion, three hundred twenty-three million, one hundred forty-six thousand, six hundred fifty-five".