37721993 has 2 divisors, whose sum is σ = 37721994. Its totient is φ = 37721992.

The previous prime is 37721989. The next prime is 37722007. The reversal of 37721993 is 39912773.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 37002889 + 719104 = 6083^2 + 848^2 .

It is a cyclic number.

It is not a de Polignac number, because 37721993 - 2² = 37721989 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 37721993.

It is not a weakly prime, because it can be changed into another prime (37721903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 18860996 + 18860997.

It is an arithmetic number, because the mean of its divisors is an integer number (18860997).

Almost surely, 2^37721993 is an apocalyptic number.

It is an amenable number.

37721993 is a deficient number, since it is larger than the sum of its proper divisors (1).

37721993 is an equidigital number, since it uses as much as digits as its factorization.

37721993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 71442, while the sum is 41.

The square root of 37721993 is about 6141.8232634943. The cubic root of 37721993 is about 335.3756623426.

The spelling of 37721993 in words is "thirty-seven million, seven hundred twenty-one thousand, nine hundred ninety-three".