31481940 has 96 divisors (see below), whose sum is σ = 105154560. Its totient is φ = 6880896.

The previous prime is 31481939. The next prime is 31481951. The reversal of 31481940 is 4918413.

It is a happy number.

It is a super-2 number, since 2×31481940² = 1982225092327200, which contains 22 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 31481898 and 31481907.

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, 8031 + ... + 11289.

It is an arithmetic number, because the mean of its divisors is an integer number (1095360).

Almost surely, 2^31481940 is an apocalyptic number.

31481940 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 31481940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (52577280).

31481940 is an abundant number, since it is smaller than the sum of its proper divisors (73672620).

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

31481940 is a wasteful number, since it uses less digits than its factorization.

31481940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3301 (or 3299 counting only the distinct ones).

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

The square root of 31481940 is about 5610.8769368077. The cubic root of 31481940 is about 315.7576120193.

The spelling of 31481940 in words is "thirty-one million, four hundred eighty-one thousand, nine hundred forty".