31143431 has 4 divisors (see below), whose sum is σ = 33974664. Its totient is φ = 28312200.

The previous prime is 31143407. The next prime is 31143433. The reversal of 31143431 is 13434113.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 31143431 - 2¹⁸ = 30881287 is a prime.

It is a super-2 number, since 2×31143431² = 1939826588903522, 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 (31143433) 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, 1415600 + ... + 1415621.

It is an arithmetic number, because the mean of its divisors is an integer number (8493666).

Almost surely, 2^31143431 is an apocalyptic number.

31143431 is a deficient number, since it is larger than the sum of its proper divisors (2831233).

31143431 is a wasteful number, since it uses less digits than its factorization.

31143431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2831232.

The product of its digits is 432, while the sum is 20.

The square root of 31143431 is about 5580.6299823586. The cubic root of 31143431 is about 314.6218052896.

Adding to 31143431 its reverse (13434113), we get a palindrome (44577544).

The spelling of 31143431 in words is "thirty-one million, one hundred forty-three thousand, four hundred thirty-one".