31197840 has 80 divisors (see below), whose sum is σ = 98344896. Its totient is φ = 8179200.

The previous prime is 31197809. The next prime is 31197841. The reversal of 31197840 is 4879113.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31197841) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13575 + ... + 15705.

Almost surely, 2^31197840 is an apocalyptic number.

31197840 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31197840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49172448).

31197840 is an abundant number, since it is smaller than the sum of its proper divisors (67147056).

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

31197840 is a wasteful number, since it uses less digits than its factorization.

31197840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2208 (or 2202 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 33.

The square root of 31197840 is about 5585.5026631450. The cubic root of 31197840 is about 314.8049182621.

The spelling of 31197840 in words is "thirty-one million, one hundred ninety-seven thousand, eight hundred forty".