40138791 has 48 divisors (see below), whose sum is σ = 68859648. Its totient is φ = 20563200.

The previous prime is 40138771. The next prime is 40138801. The reversal of 40138791 is 19783104.

It is not a de Polignac number, because 40138791 - 2¹⁵ = 40106023 is a prime.

It is a super-2 number, since 2×40138791² = 3222245085883362, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40138711) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 166431 + ... + 166671.

It is an arithmetic number, because the mean of its divisors is an integer number (1434576).

Almost surely, 2^40138791 is an apocalyptic number.

40138791 is a deficient number, since it is larger than the sum of its proper divisors (28720857).

40138791 is a wasteful number, since it uses less digits than its factorization.

40138791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 372 (or 365 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 33.

The square root of 40138791 is about 6335.5182108491. The cubic root of 40138791 is about 342.3902815128.

It can be divided in two parts, 40 and 138791, that added together give a palindrome (138831).

The spelling of 40138791 in words is "forty million, one hundred thirty-eight thousand, seven hundred ninety-one".