87855917 has 2 divisors, whose sum is σ = 87855918. Its totient is φ = 87855916.

The previous prime is 87855869. The next prime is 87855941. The reversal of 87855917 is 71955878.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 83649316 + 4206601 = 9146^2 + 2051^2 .

It is a cyclic number.

It is not a de Polignac number, because 87855917 - 2²⁴ = 71078701 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87855967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43927958 + 43927959.

It is an arithmetic number, because the mean of its divisors is an integer number (43927959).

Almost surely, 2^87855917 is an apocalyptic number.

It is an amenable number.

87855917 is a deficient number, since it is larger than the sum of its proper divisors (1).

87855917 is an equidigital number, since it uses as much as digits as its factorization.

87855917 is an evil number, because the sum of its binary digits is even.

The product of its digits is 705600, while the sum is 50.

The square root of 87855917 is about 9373.1487238814. The cubic root of 87855917 is about 444.5531296536.

The spelling of 87855917 in words is "eighty-seven million, eight hundred fifty-five thousand, nine hundred seventeen".