90981890 has 16 divisors (see below), whose sum is σ = 168194232. Its totient is φ = 35409024.

The previous prime is 90981887. The next prime is 90981893. The reversal of 90981890 is 9818909.

It is an interprime number because it is at equal distance from previous prime (90981887) and next prime (90981893).

It can be written as a sum of positive squares in 4 ways, for example, as 89510521 + 1471369 = 9461^2 + 1213^2 .

It is an alternating number because its digits alternate between odd and even.

It is not an unprimeable number, because it can be changed into a prime (90981893) 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, 122579 + ... + 123318.

Almost surely, 2^90981890 is an apocalyptic number.

90981890 is a deficient number, since it is larger than the sum of its proper divisors (77212342).

90981890 is a wasteful number, since it uses less digits than its factorization.

90981890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 245941.

The product of its (nonzero) digits is 46656, while the sum is 44.

The square root of 90981890 is about 9538.4427450187. The cubic root of 90981890 is about 449.7643045554.

The spelling of 90981890 in words is "ninety million, nine hundred eighty-one thousand, eight hundred ninety".