37820813 has 2 divisors, whose sum is σ = 37820814. Its totient is φ = 37820812.

The previous prime is 37820807. The next prime is 37820821. The reversal of 37820813 is 31802873.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 37185604 + 635209 = 6098^2 + 797^2 .

It is an emirp because it is prime and its reverse (31802873) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 37820813 - 2⁸ = 37820557 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 37820813.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (37820833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 18910406 + 18910407.

It is an arithmetic number, because the mean of its divisors is an integer number (18910407).

Almost surely, 2^37820813 is an apocalyptic number.

It is an amenable number.

37820813 is a deficient number, since it is larger than the sum of its proper divisors (1).

37820813 is an equidigital number, since it uses as much as digits as its factorization.

37820813 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 37820813 is about 6149.8628439990. The cubic root of 37820813 is about 335.6682672830.

The spelling of 37820813 in words is "thirty-seven million, eight hundred twenty thousand, eight hundred thirteen".