16400431 has 2 divisors, whose sum is σ = 16400432. Its totient is φ = 16400430.

The previous prime is 16400429. The next prime is 16400441. The reversal of 16400431 is 13400461.

It is a happy number.

16400431 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 16400431 - 2¹ = 16400429 is a prime.

It is a super-2 number, since 2×16400431² = 537948273971522, which contains 22 as substring.

Together with 16400429, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 16400399 and 16400408.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16400411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8200215 + 8200216.

It is an arithmetic number, because the mean of its divisors is an integer number (8200216).

Almost surely, 2^16400431 is an apocalyptic number.

16400431 is a deficient number, since it is larger than the sum of its proper divisors (1).

16400431 is an equidigital number, since it uses as much as digits as its factorization.

16400431 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 16400431 is about 4049.7445598457. The cubic root of 16400431 is about 254.0690442016.

Adding to 16400431 its reverse (13400461), we get a palindrome (29800892).

The spelling of 16400431 in words is "sixteen million, four hundred thousand, four hundred thirty-one".