90708021 has 12 divisors (see below), whose sum is σ = 136719648. Its totient is φ = 57842664.

The previous prime is 90708019. The next prime is 90708029. The reversal of 90708021 is 12080709.

It is not a de Polignac number, because 90708021 - 2¹ = 90708019 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90708029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 218895 + ... + 219308.

It is an arithmetic number, because the mean of its divisors is an integer number (11393304).

Almost surely, 2^90708021 is an apocalyptic number.

It is an amenable number.

90708021 is a deficient number, since it is larger than the sum of its proper divisors (46011627).

90708021 is a wasteful number, since it uses less digits than its factorization.

90708021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 438232 (or 438229 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The square root of 90708021 is about 9524.0758606807. The cubic root of 90708021 is about 449.3125652016.

The spelling of 90708021 in words is "ninety million, seven hundred eight thousand, twenty-one".