33390431 has 4 divisors (see below), whose sum is σ = 35354592. Its totient is φ = 31426272.

The previous prime is 33390421. The next prime is 33390433. The reversal of 33390431 is 13409333.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13409333 = 7 ⋅1915619.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-33390431 is a prime.

It is a super-2 number, since 2×33390431² = 2229841764731522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 33390431.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (33390433) 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, 982055 + ... + 982088.

It is an arithmetic number, because the mean of its divisors is an integer number (8838648).

Almost surely, 2^33390431 is an apocalyptic number.

33390431 is a deficient number, since it is larger than the sum of its proper divisors (1964161).

33390431 is a wasteful number, since it uses less digits than its factorization.

33390431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1964160.

The product of its (nonzero) digits is 2916, while the sum is 26.

The square root of 33390431 is about 5778.4453791656. The cubic root of 33390431 is about 322.0134473507.

Adding to 33390431 its reverse (13409333), we get a palindrome (46799764).

The spelling of 33390431 in words is "thirty-three million, three hundred ninety thousand, four hundred thirty-one".