90891081 has 6 divisors (see below), whose sum is σ = 131287130. Its totient is φ = 60594048.

The previous prime is 90891029. The next prime is 90891083. The reversal of 90891081 is 18019809.

It can be written as a sum of positive squares in only one way, i.e., 70560000 + 20331081 = 8400^2 + 4509^2 .

It is not a de Polignac number, because 90891081 - 2¹⁴ = 90874697 is a prime.

It is a super-2 number, since 2×90891081² = 16522377210697122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (90891083) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5049496 + ... + 5049513.

Almost surely, 2^90891081 is an apocalyptic number.

It is an amenable number.

90891081 is a deficient number, since it is larger than the sum of its proper divisors (40396049).

90891081 is a wasteful number, since it uses less digits than its factorization.

90891081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10099015 (or 10099012 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 36.

The square root of 90891081 is about 9533.6813980749. The cubic root of 90891081 is about 449.6146181998.

The spelling of 90891081 in words is "ninety million, eight hundred ninety-one thousand, eighty-one".