90471581 has 4 divisors (see below), whose sum is σ = 94405152. Its totient is φ = 86538012.

The previous prime is 90471533. The next prime is 90471593. The reversal of 90471581 is 18517409.

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: 18517409 = 197 ⋅93997.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-90471581 is a prime.

It is a super-2 number, since 2×90471581² = 16370213937279122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90471181) 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, 1966751 + ... + 1966796.

It is an arithmetic number, because the mean of its divisors is an integer number (23601288).

Almost surely, 2^90471581 is an apocalyptic number.

It is an amenable number.

90471581 is a deficient number, since it is larger than the sum of its proper divisors (3933571).

90471581 is a wasteful number, since it uses less digits than its factorization.

90471581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3933570.

The product of its (nonzero) digits is 10080, while the sum is 35.

The square root of 90471581 is about 9511.6550084620. The cubic root of 90471581 is about 448.9218320180.

The spelling of 90471581 in words is "ninety million, four hundred seventy-one thousand, five hundred eighty-one".