215531025520155 has 64 divisors (see below), whose sum is σ = 347905090372608. Its totient is φ = 113935327418880.

The previous prime is 215531025520079. The next prime is 215531025520177. The reversal of 215531025520155 is 551025520135512.

It is not a de Polignac number, because 215531025520155 - 2⁸ = 215531025519899 is a prime.

It is a super-2 number, since 2×215531025520155² (a number of 29 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 6015193090 + ... + 6015228920.

It is an arithmetic number, because the mean of its divisors is an integer number (5436017037072).

Almost surely, 2^{215531025520155} is an apocalyptic number.

215531025520155 is a deficient number, since it is larger than the sum of its proper divisors (132374064852453).

215531025520155 is a wasteful number, since it uses less digits than its factorization.

215531025520155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42596.

The product of its (nonzero) digits is 375000, while the sum is 42.

Adding to 215531025520155 its reverse (551025520135512), we get a palindrome (766556545655667).

The spelling of 215531025520155 in words is "two hundred fifteen trillion, five hundred thirty-one billion, twenty-five million, five hundred twenty thousand, one hundred fifty-five".