40138818 has 16 divisors (see below), whose sum is σ = 83768256. Its totient is φ = 12797840.

The previous prime is 40138817. The next prime is 40138837. The reversal of 40138818 is 81883104.

It is a happy number.

It is a super-2 number, since 2×40138818² = 3222249420874248, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (40138817) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 145293 + ... + 145568.

It is an arithmetic number, because the mean of its divisors is an integer number (5235516).

Almost surely, 2^40138818 is an apocalyptic number.

40138818 is an abundant number, since it is smaller than the sum of its proper divisors (43629438).

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

40138818 is a wasteful number, since it uses less digits than its factorization.

40138818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 290889.

The product of its (nonzero) digits is 6144, while the sum is 33.

The square root of 40138818 is about 6335.5203416925. The cubic root of 40138818 is about 342.3903582842.

The spelling of 40138818 in words is "forty million, one hundred thirty-eight thousand, eight hundred eighteen".