40139978 has 16 divisors (see below), whose sum is σ = 62407680. Its totient is φ = 19342800.

The previous prime is 40139977. The next prime is 40139993. The reversal of 40139978 is 87993104.

It is a happy number.

40139978 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×40139978² = 3222435667680968, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (40139971) 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, 15608 + ... + 17996.

It is an arithmetic number, because the mean of its divisors is an integer number (3900480).

Almost surely, 2^40139978 is an apocalyptic number.

40139978 is a deficient number, since it is larger than the sum of its proper divisors (22267702).

40139978 is a wasteful number, since it uses less digits than its factorization.

40139978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2693.

The product of its (nonzero) digits is 54432, while the sum is 41.

The square root of 40139978 is about 6335.6118883656. The cubic root of 40139978 is about 342.3936565792.

The spelling of 40139978 in words is "forty million, one hundred thirty-nine thousand, nine hundred seventy-eight".