31440436 has 6 divisors (see below), whose sum is σ = 55020770. Its totient is φ = 15720216.

The previous prime is 31440427. The next prime is 31440449. The reversal of 31440436 is 63404413.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 22619536 + 8820900 = 4756^2 + 2970^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 31440436.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3930051 + ... + 3930058.

Almost surely, 2^31440436 is an apocalyptic number.

It is an amenable number.

31440436 is a deficient number, since it is larger than the sum of its proper divisors (23580334).

31440436 is a wasteful number, since it uses less digits than its factorization.

31440436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7860113 (or 7860111 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 25.

The square root of 31440436 is about 5607.1771864281. The cubic root of 31440436 is about 315.6187920355.

Adding to 31440436 its reverse (63404413), we get a palindrome (94844849).

The spelling of 31440436 in words is "thirty-one million, four hundred forty thousand, four hundred thirty-six".