40079781 has 24 divisors (see below), whose sum is σ = 67009280. Its totient is φ = 22610016.

The previous prime is 40079737. The next prime is 40079783. The reversal of 40079781 is 18797004.

It is not a de Polignac number, because 40079781 - 2⁶ = 40079717 is a prime.

It is a super-2 number, since 2×40079781² = 3212777690015922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40079783) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 951 + ... + 9003.

Almost surely, 2^40079781 is an apocalyptic number.

It is an amenable number.

40079781 is a deficient number, since it is larger than the sum of its proper divisors (26929499).

40079781 is a wasteful number, since it uses less digits than its factorization.

40079781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8145 (or 8142 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 36.

The square root of 40079781 is about 6330.8594203315. The cubic root of 40079781 is about 342.2224109875. Note that the first 3 decimals are identical.

The spelling of 40079781 in words is "forty million, seventy-nine thousand, seven hundred eighty-one".