40640436 has 18 divisors (see below), whose sum is σ = 102730082. Its totient is φ = 13546800.

The previous prime is 40640417. The next prime is 40640437. The reversal of 40640436 is 63404604.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 40068900 + 571536 = 6330^2 + 756^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40640437) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 564415 + ... + 564486.

Almost surely, 2^40640436 is an apocalyptic number.

It is an amenable number.

40640436 is an abundant number, since it is smaller than the sum of its proper divisors (62089646).

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

40640436 is a wasteful number, since it uses less digits than its factorization.

40640436 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1128911 (or 1128906 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 27.

The square root of 40640436 is about 6374.9851764534. The cubic root of 40640436 is about 343.8107508717.

The spelling of 40640436 in words is "forty million, six hundred forty thousand, four hundred thirty-six".