6405431 has 4 divisors (see below), whose sum is σ = 6683952. Its totient is φ = 6126912.

The previous prime is 6405397. The next prime is 6405457. The reversal of 6405431 is 1345046.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 6405431 - 2⁶ = 6405367 is a prime.

It is a super-2 number, since 2×6405431² = 82059092591522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (23), and also a Moran number because the ratio is a prime number: 278497 = 6405431 / (6 + 4 + 0 + 5 + 4 + 3 + 1).

It is an Ulam number.

It is a d-powerful number, because it can be written as 6⁸ + 4³ + 0 + 5 + 4¹¹ + 3¹² + 1 .

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 6405397 and 6405406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6405461) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 139226 + ... + 139271.

It is an arithmetic number, because the mean of its divisors is an integer number (1670988).

Almost surely, 2^6405431 is an apocalyptic number.

6405431 is a deficient number, since it is larger than the sum of its proper divisors (278521).

6405431 is a wasteful number, since it uses less digits than its factorization.

6405431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 278520.

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 6405431 is about 2530.8952961353. The cubic root of 6405431 is about 185.7160561398.

The spelling of 6405431 in words is "six million, four hundred five thousand, four hundred thirty-one".