405813823 has 4 divisors (see below), whose sum is σ = 406087128. Its totient is φ = 405540520.

The previous prime is 405813787. The next prime is 405813869. The reversal of 405813823 is 328318504.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-405813823 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (405813883) 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, 134413 + ... + 137398.

It is an arithmetic number, because the mean of its divisors is an integer number (101521782).

Almost surely, 2^405813823 is an apocalyptic number.

405813823 is a deficient number, since it is larger than the sum of its proper divisors (273305).

405813823 is a wasteful number, since it uses less digits than its factorization.

405813823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 273304.

The product of its (nonzero) digits is 23040, while the sum is 34.

The square root of 405813823 is about 20144.8212451737. The cubic root of 405813823 is about 740.3588611269.

The spelling of 405813823 in words is "four hundred five million, eight hundred thirteen thousand, eight hundred twenty-three".