31438013 has 2 divisors, whose sum is σ = 31438014. Its totient is φ = 31438012.

The previous prime is 31438007. The next prime is 31438037. The reversal of 31438013 is 31083413.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 29300569 + 2137444 = 5413^2 + 1462^2 .

It is an emirp because it is prime and its reverse (31083413) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31438013 - 2¹⁰ = 31436989 is a prime.

It is a super-2 number, since 2×31438013² = 1976697322776338, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 31438013.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31438073) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15719006 + 15719007.

It is an arithmetic number, because the mean of its divisors is an integer number (15719007).

Almost surely, 2^31438013 is an apocalyptic number.

It is an amenable number.

31438013 is a deficient number, since it is larger than the sum of its proper divisors (1).

31438013 is an equidigital number, since it uses as much as digits as its factorization.

31438013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 31438013 is about 5606.9611198937. The cubic root of 31438013 is about 315.6106839633.

The spelling of 31438013 in words is "thirty-one million, four hundred thirty-eight thousand, thirteen".