400064399 has 16 divisors (see below), whose sum is σ = 487092480. Its totient is φ = 320941440.

The previous prime is 400064381. The next prime is 400064419. The reversal of 400064399 is 993460004.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 400064399 - 2²⁴ = 383287183 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400064359) 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, 7082 + ... + 29159.

It is an arithmetic number, because the mean of its divisors is an integer number (30443280).

Almost surely, 2^400064399 is an apocalyptic number.

400064399 is a deficient number, since it is larger than the sum of its proper divisors (87028081).

400064399 is a wasteful number, since it uses less digits than its factorization.

400064399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36350.

The product of its (nonzero) digits is 23328, while the sum is 35.

The square root of 400064399 is about 20001.6099102047. The cubic root of 400064399 is about 736.8458389303.

The spelling of 400064399 in words is "four hundred million, sixty-four thousand, three hundred ninety-nine".