90721357 has 4 divisors (see below), whose sum is σ = 92831200. Its totient is φ = 88611516.

The previous prime is 90721343. The next prime is 90721369. The reversal of 90721357 is 75312709.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 75312709 = 743 ⋅101363.

It is a cyclic number.

It is not a de Polignac number, because 90721357 - 2⁷ = 90721229 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90721957) 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, 1054857 + ... + 1054942.

It is an arithmetic number, because the mean of its divisors is an integer number (23207800).

Almost surely, 2^90721357 is an apocalyptic number.

It is an amenable number.

90721357 is a deficient number, since it is larger than the sum of its proper divisors (2109843).

90721357 is a wasteful number, since it uses less digits than its factorization.

90721357 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2109842.

The product of its (nonzero) digits is 13230, while the sum is 34.

The square root of 90721357 is about 9524.7759553703. The cubic root of 90721357 is about 449.3345836099.

The spelling of 90721357 in words is "ninety million, seven hundred twenty-one thousand, three hundred fifty-seven".