40138942 has 4 divisors (see below), whose sum is σ = 60208416. Its totient is φ = 20069470.

The previous prime is 40138937. The next prime is 40138957. The reversal of 40138942 is 24983104.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×40138942² = 3222269329758728, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10034734 + ... + 10034737.

It is an arithmetic number, because the mean of its divisors is an integer number (15052104).

Almost surely, 2^40138942 is an apocalyptic number.

40138942 is a deficient number, since it is larger than the sum of its proper divisors (20069474).

40138942 is a wasteful number, since it uses less digits than its factorization.

40138942 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20069473.

The product of its (nonzero) digits is 6912, while the sum is 31.

The square root of 40138942 is about 6335.5301277794. The cubic root of 40138942 is about 342.3907108636.

The spelling of 40138942 in words is "forty million, one hundred thirty-eight thousand, nine hundred forty-two".