37978991 has 2 divisors, whose sum is σ = 37978992. Its totient is φ = 37978990.

The previous prime is 37978987. The next prime is 37979033. The reversal of 37978991 is 19987973.

37978991 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 37978991 - 2² = 37978987 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (37978931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 18989495 + 18989496.

It is an arithmetic number, because the mean of its divisors is an integer number (18989496).

Almost surely, 2^37978991 is an apocalyptic number.

37978991 is a deficient number, since it is larger than the sum of its proper divisors (1).

37978991 is an equidigital number, since it uses as much as digits as its factorization.

37978991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 857304, while the sum is 53.

The square root of 37978991 is about 6162.7097124560. The cubic root of 37978991 is about 336.1355715904.

The spelling of 37978991 in words is "thirty-seven million, nine hundred seventy-eight thousand, nine hundred ninety-one".