37840721 has 2 divisors, whose sum is σ = 37840722. Its totient is φ = 37840720.

The previous prime is 37840709. The next prime is 37840757. The reversal of 37840721 is 12704873.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 31764496 + 6076225 = 5636^2 + 2465^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-37840721 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (37840021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 18920360 + 18920361.

It is an arithmetic number, because the mean of its divisors is an integer number (18920361).

Almost surely, 2^37840721 is an apocalyptic number.

It is an amenable number.

37840721 is a deficient number, since it is larger than the sum of its proper divisors (1).

37840721 is an equidigital number, since it uses as much as digits as its factorization.

37840721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9408, while the sum is 32.

The square root of 37840721 is about 6151.4812037427. The cubic root of 37840721 is about 335.7271529527.

The spelling of 37840721 in words is "thirty-seven million, eight hundred forty thousand, seven hundred twenty-one".