431221421 has 16 divisors (see below), whose sum is σ = 451914240. Its totient is φ = 411091200.

The previous prime is 431221403. The next prime is 431221423. The reversal of 431221421 is 124122134.

It is a cyclic number.

It is not a de Polignac number, because 431221421 - 2²⁶ = 364112557 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 431221393 and 431221402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (431221423) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 440885 + ... + 441861.

It is an arithmetic number, because the mean of its divisors is an integer number (28244640).

Almost surely, 2^431221421 is an apocalyptic number.

It is an amenable number.

431221421 is a deficient number, since it is larger than the sum of its proper divisors (20692819).

431221421 is a wasteful number, since it uses less digits than its factorization.

431221421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1244.

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

The square root of 431221421 is about 20765.8715444356. The cubic root of 431221421 is about 755.4982142093.

Adding to 431221421 its reverse (124122134), we get a palindrome (555343555).

The spelling of 431221421 in words is "four hundred thirty-one million, two hundred twenty-one thousand, four hundred twenty-one".