31949840 has 80 divisors (see below), whose sum is σ = 82661376. Its totient is φ = 11404800.

The previous prime is 31949807. The next prime is 31949867. The reversal of 31949840 is 4894913.

It is a tau number, because it is divible by the number of its divisors (80).

It is a junction number, because it is equal to n+sod(n) for n = 31949794 and 31949803.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31745 + ... + 32735.

Almost surely, 2^31949840 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31949840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41330688).

31949840 is an abundant number, since it is smaller than the sum of its proper divisors (50711536).

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

31949840 is a wasteful number, since it uses less digits than its factorization.

31949840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1048 (or 1042 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 38.

The square root of 31949840 is about 5652.4189512102. The cubic root of 31949840 is about 317.3142402341.

The spelling of 31949840 in words is "thirty-one million, nine hundred forty-nine thousand, eight hundred forty".