215118788481 has 81 divisors (see below), whose sum is σ = 335401671969. Its totient is φ = 132842318544.

The previous prime is 215118788473. The next prime is 215118788491. The reversal of 215118788481 is 184887811512.

The square root of 215118788481 is 463809.

It is a perfect power (a square), and thus also a powerful number.

215118788481 is a `hidden beast` number, since 2 + 1 + 5 + 1 + 1 + 87 + 88 + 481 = 666.

It is not a de Polignac number, because 215118788481 - 2³ = 215118788473 is a prime.

It is a super-2 number, since 2×215118788481² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (215118788411) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 2088531876 + ... + 2088531978.

Almost surely, 2^215118788481 is an apocalyptic number.

215118788481 is the 463809-th square number.

215118788481 is the 231905-th centered octagonal number.

It is an amenable number.

215118788481 is a deficient number, since it is larger than the sum of its proper divisors (120282883488).

215118788481 is an equidigital number, since it uses as much as digits as its factorization.

215118788481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 408 (or 204 counting only the distinct ones).

The product of its digits is 1146880, while the sum is 54.

The spelling of 215118788481 in words is "two hundred fifteen billion, one hundred eighteen million, seven hundred eighty-eight thousand, four hundred eighty-one".