31440431 has 4 divisors (see below), whose sum is σ = 34298664. Its totient is φ = 28582200.

The previous prime is 31440427. The next prime is 31440449. The reversal of 31440431 is 13404413.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13404413 = 11 ⋅1218583.

It is a cyclic number.

It is not a de Polignac number, because 31440431 - 2² = 31440427 is a prime.

It is a super-2 number, since 2×31440431² = 1977001402931522, 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 (31440401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1429100 + ... + 1429121.

It is an arithmetic number, because the mean of its divisors is an integer number (8574666).

Almost surely, 2^31440431 is an apocalyptic number.

31440431 is a deficient number, since it is larger than the sum of its proper divisors (2858233).

31440431 is a wasteful number, since it uses less digits than its factorization.

31440431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2858232.

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 31440431 is about 5607.1767405710. The cubic root of 31440431 is about 315.6187753045.

Adding to 31440431 its reverse (13404413), we get a palindrome (44844844).

The spelling of 31440431 in words is "thirty-one million, four hundred forty thousand, four hundred thirty-one".