20321431 has 16 divisors (see below), whose sum is σ = 23839200. Its totient is φ = 17152128.

The previous prime is 20321423. The next prime is 20321447. The reversal of 20321431 is 13412302.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 20321431 - 2³ = 20321423 is a prime.

It is a super-2 number, since 2×20321431² = 825921115775522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20321401) 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, 5745 + ... + 8581.

It is an arithmetic number, because the mean of its divisors is an integer number (1489950).

Almost surely, 2^20321431 is an apocalyptic number.

20321431 is a deficient number, since it is larger than the sum of its proper divisors (3517769).

20321431 is a wasteful number, since it uses less digits than its factorization.

20321431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2898.

The product of its (nonzero) digits is 144, while the sum is 16.

The square root of 20321431 is about 4507.9297909351. The cubic root of 20321431 is about 272.8882035412. Note that the first 3 decimals are identical.

Adding to 20321431 its reverse (13412302), we get a palindrome (33733733).

The spelling of 20321431 in words is "twenty million, three hundred twenty-one thousand, four hundred thirty-one".