90785281 has 4 divisors (see below), whose sum is σ = 91025200. Its totient is φ = 90545364.

The previous prime is 90785273. The next prime is 90785293. The reversal of 90785281 is 18258709.

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: 18258709 = 7 ⋅2608387.

It is a cyclic number.

It is not a de Polignac number, because 90785281 - 2³ = 90785273 is a prime.

It is a super-2 number, since 2×90785281² = 16483934492497922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (90785221) 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, 119391 + ... + 120148.

It is an arithmetic number, because the mean of its divisors is an integer number (22756300).

Almost surely, 2^90785281 is an apocalyptic number.

It is an amenable number.

90785281 is a deficient number, since it is larger than the sum of its proper divisors (239919).

90785281 is a wasteful number, since it uses less digits than its factorization.

90785281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 239918.

The product of its (nonzero) digits is 40320, while the sum is 40.

The square root of 90785281 is about 9528.1310339436. The cubic root of 90785281 is about 449.4400954070.

The spelling of 90785281 in words is "ninety million, seven hundred eighty-five thousand, two hundred eighty-one".