91255987 has 2 divisors, whose sum is σ = 91255988. Its totient is φ = 91255986.

The previous prime is 91255979. The next prime is 91256021. The reversal of 91255987 is 78955219.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 91255987 - 2³ = 91255979 is a prime.

It is not a weakly prime, because it can be changed into another prime (91255187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45627993 + 45627994.

It is an arithmetic number, because the mean of its divisors is an integer number (45627994).

Almost surely, 2^91255987 is an apocalyptic number.

91255987 is a deficient number, since it is larger than the sum of its proper divisors (1).

91255987 is an equidigital number, since it uses as much as digits as its factorization.

91255987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 226800, while the sum is 46.

The square root of 91255987 is about 9552.7999560338. The cubic root of 91255987 is about 450.2155132312.

The spelling of 91255987 in words is "ninety-one million, two hundred fifty-five thousand, nine hundred eighty-seven".