231917940 has 72 divisors (see below), whose sum is σ = 705119688. Its totient is φ = 61701120.

The previous prime is 231917911. The next prime is 231917941. The reversal of 231917940 is 49719132.

It can be written as a sum of positive squares in 4 ways, for example, as 25765776 + 206152164 = 5076^2 + 14358^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 231917895 and 231917904.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231917941) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 92544 + ... + 95016.

It is an arithmetic number, because the mean of its divisors is an integer number (9793329).

Almost surely, 2^231917940 is an apocalyptic number.

231917940 is a gapful number since it is divisible by the number (20) 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 231917940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (352559844).

231917940 is an abundant number, since it is smaller than the sum of its proper divisors (473201748).

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

231917940 is a wasteful number, since it uses less digits than its factorization.

231917940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3009 (or 3004 counting only the distinct ones).

The product of its (nonzero) digits is 13608, while the sum is 36.

The square root of 231917940 is about 15228.8522220159. The cubic root of 231917940 is about 614.3909099506.

The spelling of 231917940 in words is "two hundred thirty-one million, nine hundred seventeen thousand, nine hundred forty".