90091001 has 16 divisors (see below), whose sum is σ = 120962688. Its totient is φ = 64800000.

The previous prime is 90090997. The next prime is 90091013. The reversal of 90091001 is 10019009.

It is a cyclic number.

It is not a de Polignac number, because 90091001 - 2² = 90090997 is a prime.

It is a super-2 number, since 2×90091001² = 16232776922364002, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (90091021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 44000 + ... + 46001.

It is an arithmetic number, because the mean of its divisors is an integer number (7560168).

Almost surely, 2^90091001 is an apocalyptic number.

90091001 is a gapful number since it is divisible by the number (91) formed by its first and last digit.

It is an amenable number.

90091001 is a deficient number, since it is larger than the sum of its proper divisors (30871687).

90091001 is a wasteful number, since it uses less digits than its factorization.

90091001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90032.

The product of its (nonzero) digits is 81, while the sum is 20.

The square root of 90091001 is about 9491.6279425607. The cubic root of 90091001 is about 448.2914653747.

It can be divided in two parts, 9009 and 1001, that multiplied together give a square (9018009 = 3003²).

The spelling of 90091001 in words is "ninety million, ninety-one thousand, one".