31155930 has 96 divisors (see below), whose sum is σ = 90155520. Its totient is φ = 7413120.

The previous prime is 31155923. The next prime is 31155931. The reversal of 31155930 is 3955113.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 31155894 and 31155903.

It is not an unprimeable number, because it can be changed into a prime (31155931) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 35841 + ... + 36699.

It is an arithmetic number, because the mean of its divisors is an integer number (939120).

Almost surely, 2^31155930 is an apocalyptic number.

31155930 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 31155930, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45077760).

31155930 is an abundant number, since it is smaller than the sum of its proper divisors (58999590).

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

31155930 is a wasteful number, since it uses less digits than its factorization.

31155930 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 916 (or 913 counting only the distinct ones).

The product of its (nonzero) digits is 2025, while the sum is 27.

The square root of 31155930 is about 5581.7497256685. The cubic root of 31155930 is about 314.6638894130.

It can be divided in two parts, 3115 and 5930, that added together give a triangular number (9045 = T₁₃₄).

The spelling of 31155930 in words is "thirty-one million, one hundred fifty-five thousand, nine hundred thirty".