31491480 has 128 divisors (see below), whose sum is σ = 102643200. Its totient is φ = 7698432.

The previous prime is 31491469. The next prime is 31491511. The reversal of 31491480 is 8419413.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 87541 + ... + 87899.

It is an arithmetic number, because the mean of its divisors is an integer number (801900).

Almost surely, 2^31491480 is an apocalyptic number.

31491480 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 31491480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51321600).

31491480 is an abundant number, since it is smaller than the sum of its proper divisors (71151720).

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

31491480 is a wasteful number, since it uses less digits than its factorization.

31491480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 433 (or 429 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 31491480 is about 5611.7270069026. The cubic root of 31491480 is about 315.7895035672.

The spelling of 31491480 in words is "thirty-one million, four hundred ninety-one thousand, four hundred eighty".