38697991 has 2 divisors, whose sum is σ = 38697992. Its totient is φ = 38697990.

The previous prime is 38697961. The next prime is 38698007. The reversal of 38697991 is 19979683.

38697991 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 38697991 - 2⁵ = 38697959 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (38697961) 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, 19348995 + 19348996.

It is an arithmetic number, because the mean of its divisors is an integer number (19348996).

Almost surely, 2^38697991 is an apocalyptic number.

38697991 is a deficient number, since it is larger than the sum of its proper divisors (1).

38697991 is an equidigital number, since it uses as much as digits as its factorization.

38697991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 734832, while the sum is 52.

The square root of 38697991 is about 6220.7709329311. The cubic root of 38697991 is about 338.2435105505.

The spelling of 38697991 in words is "thirty-eight million, six hundred ninety-seven thousand, nine hundred ninety-one".