37991987 has 8 divisors (see below), whose sum is σ = 41549760. Its totient is φ = 34451560.

The previous prime is 37991983. The next prime is 37992013. The reversal of 37991987 is 78919973.

37991987 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 37991987 - 2² = 37991983 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (37991983) 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 in 7 ways as a sum of consecutive naturals, for example, 488 + ... + 8730.

It is an arithmetic number, because the mean of its divisors is an integer number (5193720).

Almost surely, 2^37991987 is an apocalyptic number.

37991987 is a deficient number, since it is larger than the sum of its proper divisors (3557773).

37991987 is a wasteful number, since it uses less digits than its factorization.

37991987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8673.

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

The square root of 37991987 is about 6163.7640285786. The cubic root of 37991987 is about 336.1739078705.

The spelling of 37991987 in words is "thirty-seven million, nine hundred ninety-one thousand, nine hundred eighty-seven".