21231401420 has 48 divisors (see below), whose sum is σ = 48201051360. Its totient is φ = 7828130304.

The previous prime is 21231401413. The next prime is 21231401431. The reversal of 21231401420 is 2410413212.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 21231401392 and 21231401401.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 740969 + ... + 769088.

It is an arithmetic number, because the mean of its divisors is an integer number (1004188570).

Almost surely, 2^21231401420 is an apocalyptic number.

21231401420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21231401420 is an abundant number, since it is smaller than the sum of its proper divisors (26969649940).

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

21231401420 is a wasteful number, since it uses less digits than its factorization.

21231401420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1510122 (or 1510120 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 21231401420 its reverse (2410413212), we get a palindrome (23641814632).

The spelling of 21231401420 in words is "twenty-one billion, two hundred thirty-one million, four hundred one thousand, four hundred twenty".