215442631645551 has 24 divisors (see below), whose sum is σ = 328809718757520. Its totient is φ = 140918450879232.

The previous prime is 215442631645547. The next prime is 215442631645561. The reversal of 215442631645551 is 155546136244512.

215442631645551 is a `hidden beast` number, since 2 + 1 + 5 + 4 + 4 + 26 + 3 + 1 + 64 + 5 + 551 = 666.

It is not a de Polignac number, because 215442631645551 - 2² = 215442631645547 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215442631645561) 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, 8364092706 + ... + 8364118463.

It is an arithmetic number, because the mean of its divisors is an integer number (13700404948230).

Almost surely, 2^{215442631645551} is an apocalyptic number.

215442631645551 is a deficient number, since it is larger than the sum of its proper divisors (113367087111969).

215442631645551 is an equidigital number, since it uses as much as digits as its factorization.

215442631645551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16728211237 (or 16728211225 counting only the distinct ones).

The product of its digits is 17280000, while the sum is 54.

The spelling of 215442631645551 in words is "two hundred fifteen trillion, four hundred forty-two billion, six hundred thirty-one million, six hundred forty-five thousand, five hundred fifty-one".