231771540 has 384 divisors, whose sum is σ = 926650368. Its totient is φ = 41656320.

The previous prime is 231771521. The next prime is 231771581. The reversal of 231771540 is 45177132.

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 = 231771498 and 231771507.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 1020907 + ... + 1021133.

It is an arithmetic number, because the mean of its divisors is an integer number (2413152).

Almost surely, 2^231771540 is an apocalyptic number.

231771540 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 231771540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (463325184).

231771540 is an abundant number, since it is smaller than the sum of its proper divisors (694878828).

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

231771540 is a wasteful number, since it uses less digits than its factorization.

231771540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 287 (or 285 counting only the distinct ones).

The product of its (nonzero) digits is 5880, while the sum is 30.

The square root of 231771540 is about 15224.0447976220. The cubic root of 231771540 is about 614.2616030609.

The spelling of 231771540 in words is "two hundred thirty-one million, seven hundred seventy-one thousand, five hundred forty".