37900721 has 2 divisors, whose sum is σ = 37900722. Its totient is φ = 37900720.

The previous prime is 37900699. The next prime is 37900729. The reversal of 37900721 is 12700973.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 35224225 + 2676496 = 5935^2 + 1636^2 .

It is a cyclic number.

It is not a de Polignac number, because 37900721 - 2¹⁸ = 37638577 is a prime.

It is not a weakly prime, because it can be changed into another prime (37900729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 18950360 + 18950361.

It is an arithmetic number, because the mean of its divisors is an integer number (18950361).

Almost surely, 2^37900721 is an apocalyptic number.

It is an amenable number.

37900721 is a deficient number, since it is larger than the sum of its proper divisors (1).

37900721 is an equidigital number, since it uses as much as digits as its factorization.

37900721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2646, while the sum is 29.

The square root of 37900721 is about 6156.3561462930. The cubic root of 37900721 is about 335.9045015116.

The spelling of 37900721 in words is "thirty-seven million, nine hundred thousand, seven hundred twenty-one".