431621820 has 144 divisors (see below), whose sum is σ = 1501456320. Its totient is φ = 98316288.

The previous prime is 431621807. The next prime is 431621833. The reversal of 431621820 is 28126134.

431621820 is a `hidden beast` number, since 4 + 31 + 621 + 8 + 2 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (431621807) and next prime (431621833).

It is a super-2 number, since 2×431621820² = 372594791000224800, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 641004 + ... + 641676.

It is an arithmetic number, because the mean of its divisors is an integer number (10426780).

Almost surely, 2^431621820 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 431621820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (750728160).

431621820 is an abundant number, since it is smaller than the sum of its proper divisors (1069834500).

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

431621820 is a wasteful number, since it uses less digits than its factorization.

431621820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1204 (or 1199 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 431621820 is about 20775.5101020408. The cubic root of 431621820 is about 755.7319743587.

Adding to 431621820 its reverse (28126134), we get a palindrome (459747954).

The spelling of 431621820 in words is "four hundred thirty-one million, six hundred twenty-one thousand, eight hundred twenty".