90739021 has 4 divisors (see below), whose sum is σ = 92451132. Its totient is φ = 89026912.

The previous prime is 90739009. The next prime is 90739037. The reversal of 90739021 is 12093709.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 44689225 + 46049796 = 6685^2 + 6786^2 .

It is a cyclic number.

It is not a de Polignac number, because 90739021 - 2²³ = 82350413 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90739921) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 855976 + ... + 856081.

It is an arithmetic number, because the mean of its divisors is an integer number (23112783).

Almost surely, 2^90739021 is an apocalyptic number.

It is an amenable number.

90739021 is a deficient number, since it is larger than the sum of its proper divisors (1712111).

90739021 is a wasteful number, since it uses less digits than its factorization.

90739021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1712110.

The product of its (nonzero) digits is 3402, while the sum is 31.

The square root of 90739021 is about 9525.7031761440. The cubic root of 90739021 is about 449.3637444429.

The spelling of 90739021 in words is "ninety million, seven hundred thirty-nine thousand, twenty-one".