90217985 has 64 divisors (see below), whose sum is σ = 139104000. Its totient is φ = 55157760.

The previous prime is 90217973. The next prime is 90217987. The reversal of 90217985 is 58971209.

It is not a de Polignac number, because 90217985 - 2²² = 86023681 is a prime.

It is not an unprimeable number, because it can be changed into a prime (90217987) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 393851 + ... + 394079.

It is an arithmetic number, because the mean of its divisors is an integer number (2173500).

Almost surely, 2^90217985 is an apocalyptic number.

90217985 is a gapful number since it is divisible by the number (95) formed by its first and last digit.

It is an amenable number.

90217985 is a deficient number, since it is larger than the sum of its proper divisors (48886015).

90217985 is a wasteful number, since it uses less digits than its factorization.

90217985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 306.

The product of its (nonzero) digits is 45360, while the sum is 41.

The square root of 90217985 is about 9498.3148505406. The cubic root of 90217985 is about 448.5019899847.

The spelling of 90217985 in words is "ninety million, two hundred seventeen thousand, nine hundred eighty-five".