37620721 has 2 divisors, whose sum is σ = 37620722. Its totient is φ = 37620720.

The previous prime is 37620707. The next prime is 37620733. The reversal of 37620721 is 12702673.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28740321 + 8880400 = 5361^2 + 2980^2 .

It is a cyclic number.

It is not a de Polignac number, because 37620721 - 2⁵ = 37620689 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 37620721.

It is not a weakly prime, because it can be changed into another prime (37620761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 18810360 + 18810361.

It is an arithmetic number, because the mean of its divisors is an integer number (18810361).

Almost surely, 2^37620721 is an apocalyptic number.

It is an amenable number.

37620721 is a deficient number, since it is larger than the sum of its proper divisors (1).

37620721 is an equidigital number, since it uses as much as digits as its factorization.

37620721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3528, while the sum is 28.

The square root of 37620721 is about 6133.5732652345. The cubic root of 37620721 is about 335.0752663733.

The spelling of 37620721 in words is "thirty-seven million, six hundred twenty thousand, seven hundred twenty-one".