31445840 has 20 divisors (see below), whose sum is σ = 73111764. Its totient is φ = 12578304.

The previous prime is 31445833. The next prime is 31445849. The reversal of 31445840 is 4854413.

It can be written as a sum of positive squares in 2 ways, for example, as 18079504 + 13366336 = 4252^2 + 3656^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31445849) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 196457 + ... + 196616.

Almost surely, 2^31445840 is an apocalyptic number.

It is an amenable number.

31445840 is an abundant number, since it is smaller than the sum of its proper divisors (41665924).

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

31445840 is a wasteful number, since it uses less digits than its factorization.

31445840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 393086 (or 393080 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 29.

The square root of 31445840 is about 5607.6590481234. The cubic root of 31445840 is about 315.6368739120.

The spelling of 31445840 in words is "thirty-one million, four hundred forty-five thousand, eight hundred forty".