31820401 has 2 divisors, whose sum is σ = 31820402. Its totient is φ = 31820400.

The previous prime is 31820359. The next prime is 31820417. The reversal of 31820401 is 10402813.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 31640625 + 179776 = 5625^2 + 424^2 .

It is an emirp because it is prime and its reverse (10402813) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 31820401 - 2⁷ = 31820273 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (31820441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15910200 + 15910201.

It is an arithmetic number, because the mean of its divisors is an integer number (15910201).

Almost surely, 2^31820401 is an apocalyptic number.

It is an amenable number.

31820401 is a deficient number, since it is larger than the sum of its proper divisors (1).

31820401 is an equidigital number, since it uses as much as digits as its factorization.

31820401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 31820401 is about 5640.9574541916. The cubic root of 31820401 is about 316.8851464889.

The spelling of 31820401 in words is "thirty-one million, eight hundred twenty thousand, four hundred one".