215889137 has 8 divisors (see below), whose sum is σ = 236471400. Its totient is φ = 196182784.

The previous prime is 215889131. The next prime is 215889143. The reversal of 215889137 is 731988512.

It is an interprime number because it is at equal distance from previous prime (215889131) and next prime (215889143).

It can be written as a sum of positive squares in 4 ways, for example, as 11999296 + 203889841 = 3464^2 + 14279^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 215889137 - 2¹² = 215885041 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (215889131) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 218462 + ... + 219447.

It is an arithmetic number, because the mean of its divisors is an integer number (29558925).

Almost surely, 2^215889137 is an apocalyptic number.

It is an amenable number.

215889137 is a deficient number, since it is larger than the sum of its proper divisors (20582263).

215889137 is a wasteful number, since it uses less digits than its factorization.

215889137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 437955.

The product of its digits is 120960, while the sum is 44.

The square root of 215889137 is about 14693.1663367703. The cubic root of 215889137 is about 599.8973315070.

The spelling of 215889137 in words is "two hundred fifteen million, eight hundred eighty-nine thousand, one hundred thirty-seven".