90251021 has 8 divisors (see below), whose sum is σ = 103203264. Its totient is φ = 77313600.

The previous prime is 90251017. The next prime is 90251027. The reversal of 90251021 is 12015209.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 90251021 - 2² = 90251017 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 90250984 and 90251002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90251027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17306 + ... + 21908.

It is an arithmetic number, because the mean of its divisors is an integer number (12900408).

Almost surely, 2^90251021 is an apocalyptic number.

It is an amenable number.

90251021 is a deficient number, since it is larger than the sum of its proper divisors (12952243).

90251021 is a wasteful number, since it uses less digits than its factorization.

90251021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7411.

The product of its (nonzero) digits is 180, while the sum is 20.

The square root of 90251021 is about 9500.0537366901. The cubic root of 90251021 is about 448.5567274208.

The spelling of 90251021 in words is "ninety million, two hundred fifty-one thousand, twenty-one".