90040831 has 4 divisors (see below), whose sum is σ = 91384792. Its totient is φ = 88696872.

The previous prime is 90040813. The next prime is 90040871. The reversal of 90040831 is 13804009.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13804009 = 53 ⋅260453.

It is a cyclic number.

It is not a de Polignac number, because 90040831 - 2⁹ = 90040319 is a prime.

It is a super-2 number, since 2×90040831² = 16214702494341122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 90040796 and 90040805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90040871) 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, 671880 + ... + 672013.

It is an arithmetic number, because the mean of its divisors is an integer number (22846198).

Almost surely, 2^90040831 is an apocalyptic number.

90040831 is a deficient number, since it is larger than the sum of its proper divisors (1343961).

90040831 is a wasteful number, since it uses less digits than its factorization.

90040831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1343960.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 90040831 is about 9488.9847191362. The cubic root of 90040831 is about 448.2082348679.

The spelling of 90040831 in words is "ninety million, forty thousand, eight hundred thirty-one".