90071993 has 4 divisors (see below), whose sum is σ = 98260368. Its totient is φ = 81883620.

The previous prime is 90071987. The next prime is 90072013. The reversal of 90071993 is 39917009.

It is a happy number.

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: 39917009 = 11 ⋅3628819.

It is a cyclic number.

It is not a de Polignac number, because 90071993 - 2¹⁰ = 90070969 is a prime.

It is a super-2 number, since 2×90071993² = 16225927845984098, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (90071903) 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, 4094171 + ... + 4094192.

It is an arithmetic number, because the mean of its divisors is an integer number (24565092).

Almost surely, 2^90071993 is an apocalyptic number.

It is an amenable number.

90071993 is a deficient number, since it is larger than the sum of its proper divisors (8188375).

90071993 is a wasteful number, since it uses less digits than its factorization.

90071993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8188374.

The product of its (nonzero) digits is 15309, while the sum is 38.

The square root of 90071993 is about 9490.6265862692. The cubic root of 90071993 is about 448.2599353164.

The spelling of 90071993 in words is "ninety million, seventy-one thousand, nine hundred ninety-three".