37978640 has 40 divisors (see below), whose sum is σ = 100916160. Its totient is φ = 13021056.

The previous prime is 37978621. The next prime is 37978643. The reversal of 37978640 is 4687973.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 37978591 and 37978600.

It is not an unprimeable number, because it can be changed into a prime (37978643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33350 + ... + 34469.

It is an arithmetic number, because the mean of its divisors is an integer number (2522904).

Almost surely, 2^37978640 is an apocalyptic number.

It is an amenable number.

37978640 is an abundant number, since it is smaller than the sum of its proper divisors (62937520).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

37978640 is a wasteful number, since it uses less digits than its factorization.

37978640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67839 (or 67833 counting only the distinct ones).

The product of its (nonzero) digits is 254016, while the sum is 44.

The square root of 37978640 is about 6162.6812346575. The cubic root of 37978640 is about 336.1345360710.

The spelling of 37978640 in words is "thirty-seven million, nine hundred seventy-eight thousand, six hundred forty".