31009431 has 8 divisors (see below), whose sum is σ = 41378800. Its totient is φ = 20656512.

The previous prime is 31009427. The next prime is 31009457. The reversal of 31009431 is 13490013.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 31009431 - 2² = 31009427 is a prime.

It is a super-2 number, since 2×31009431² = 1923169621887522, 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 = 31009398 and 31009407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31009421) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1311 + ... + 7983.

It is an arithmetic number, because the mean of its divisors is an integer number (5172350).

Almost surely, 2^31009431 is an apocalyptic number.

31009431 is a deficient number, since it is larger than the sum of its proper divisors (10369369).

31009431 is a wasteful number, since it uses less digits than its factorization.

31009431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8225.

The product of its (nonzero) digits is 324, while the sum is 21.

The square root of 31009431 is about 5568.6112272271. The cubic root of 31009431 is about 314.1699183113.

Adding to 31009431 its reverse (13490013), we get a palindrome (44499444).

The spelling of 31009431 in words is "thirty-one million, nine thousand, four hundred thirty-one".