31139040 has 96 divisors (see below), whose sum is σ = 101515680. Its totient is φ = 8013824.

The previous prime is 31139039. The next prime is 31139041. The reversal of 31139040 is 4093113.

It is an interprime number because it is at equal distance from previous prime (31139039) and next prime (31139041).

It is a tau number, because it is divible by the number of its divisors (96).

It is a junction number, because it is equal to n+sod(n) for n = 31138998 and 31139016.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31139041) 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, 12802 + ... + 15038.

It is an arithmetic number, because the mean of its divisors is an integer number (1057455).

Almost surely, 2^31139040 is an apocalyptic number.

31139040 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 31139040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50757840).

31139040 is an abundant number, since it is smaller than the sum of its proper divisors (70376640).

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

31139040 is a wasteful number, since it uses less digits than its factorization.

31139040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2284 (or 2276 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 21.

The square root of 31139040 is about 5580.2365541256. The cubic root of 31139040 is about 314.6070181233.

The spelling of 31139040 in words is "thirty-one million, one hundred thirty-nine thousand, forty".