231015540 has 192 divisors, whose sum is σ = 767950848. Its totient is φ = 50803200.

The previous prime is 231015527. The next prime is 231015553. The reversal of 231015540 is 45510132.

It is an interprime number because it is at equal distance from previous prime (231015527) and next prime (231015553).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1818957 + ... + 1819083.

It is an arithmetic number, because the mean of its divisors is an integer number (3999744).

Almost surely, 2^231015540 is an apocalyptic number.

231015540 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 231015540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (383975424).

231015540 is an abundant number, since it is smaller than the sum of its proper divisors (536935308).

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

231015540 is a wasteful number, since it uses less digits than its factorization.

231015540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 278 (or 276 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 231015540 is about 15199.1953734400. The cubic root of 231015540 is about 613.5930027074.

Adding to 231015540 its reverse (45510132), we get a palindrome (276525672).

The spelling of 231015540 in words is "two hundred thirty-one million, fifteen thousand, five hundred forty".