231720420 has 24 divisors (see below), whose sum is σ = 648817344. Its totient is φ = 61792096.

The previous prime is 231720413. The next prime is 231720431. The reversal of 231720420 is 24027132.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1930944 + ... + 1931063.

It is an arithmetic number, because the mean of its divisors is an integer number (27034056).

Almost surely, 2^231720420 is an apocalyptic number.

231720420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

231720420 is an abundant number, since it is smaller than the sum of its proper divisors (417096924).

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

231720420 is a wasteful number, since it uses less digits than its factorization.

231720420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3862019 (or 3862017 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 21.

The square root of 231720420 is about 15222.3657819670. The cubic root of 231720420 is about 614.2164388128.

Adding to 231720420 its reverse (24027132), we get a palindrome (255747552).

The spelling of 231720420 in words is "two hundred thirty-one million, seven hundred twenty thousand, four hundred twenty".