215999225181 has 10 divisors (see below), whose sum is σ = 322665509342. Its totient is φ = 143999483400.

The previous prime is 215999225161. The next prime is 215999225231. The reversal of 215999225181 is 181522999512.

215999225181 is a `hidden beast` number, since 2 + 15 + 9 + 99 + 22 + 518 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 136892600100 + 79106625081 = 369990^2 + 281259^2 .

It is not a de Polignac number, because 215999225181 - 2¹⁹ = 215998700893 is a prime.

It is a super-2 number, since 2×215999225181² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215999225161) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 1333328470 + ... + 1333328631.

Almost surely, 2^215999225181 is an apocalyptic number.

It is an amenable number.

215999225181 is a deficient number, since it is larger than the sum of its proper divisors (106666284161).

215999225181 is an equidigital number, since it uses as much as digits as its factorization.

215999225181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2666657113 (or 2666657104 counting only the distinct ones).

The product of its digits is 1166400, while the sum is 54.

The spelling of 215999225181 in words is "two hundred fifteen billion, nine hundred ninety-nine million, two hundred twenty-five thousand, one hundred eighty-one".