31820713 has 2 divisors, whose sum is σ = 31820714. Its totient is φ = 31820712.

The previous prime is 31820689. The next prime is 31820729. The reversal of 31820713 is 31702813.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 31775769 + 44944 = 5637^2 + 212^2 .

It is an emirp because it is prime and its reverse (31702813) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31820713 is a prime.

It is not a weakly prime, because it can be changed into another prime (31820213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15910356 + 15910357.

It is an arithmetic number, because the mean of its divisors is an integer number (15910357).

Almost surely, 2^31820713 is an apocalyptic number.

It is an amenable number.

31820713 is a deficient number, since it is larger than the sum of its proper divisors (1).

31820713 is an equidigital number, since it uses as much as digits as its factorization.

31820713 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1008, while the sum is 25.

The square root of 31820713 is about 5640.9851090036. The cubic root of 31820713 is about 316.8861821750.

The spelling of 31820713 in words is "thirty-one million, eight hundred twenty thousand, seven hundred thirteen".