231728640 has 320 divisors, whose sum is σ = 874444032. Its totient is φ = 51609600.

The previous prime is 231728639. The next prime is 231728641. The reversal of 231728640 is 46827132.

231728640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (231728639) and next prime (231728641).

It is a tau number, because it is divible by the number of its divisors (320).

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231728641) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1098135 + ... + 1098345.

Almost surely, 2^231728640 is an apocalyptic number.

231728640 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 231728640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (437222016).

231728640 is an abundant number, since it is smaller than the sum of its proper divisors (642715392).

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

231728640 is a wasteful number, since it uses less digits than its factorization.

231728640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 261 (or 245 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 33.

The square root of 231728640 is about 15222.6357770263. The cubic root of 231728640 is about 614.2237015872.

The spelling of 231728640 in words is "two hundred thirty-one million, seven hundred twenty-eight thousand, six hundred forty".