401405865 has 16 divisors (see below), whose sum is σ = 733999488. Its totient is φ = 183499776.

The previous prime is 401405863. The next prime is 401405869. The reversal of 401405865 is 568504104.

It is not a de Polignac number, because 401405865 - 2¹ = 401405863 is a prime.

It is a super-2 number, since 2×401405865² = 322253336912796450, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (401405863) 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, 1911352 + ... + 1911561.

It is an arithmetic number, because the mean of its divisors is an integer number (45874968).

Almost surely, 2^401405865 is an apocalyptic number.

It is an amenable number.

401405865 is a deficient number, since it is larger than the sum of its proper divisors (332593623).

401405865 is a wasteful number, since it uses less digits than its factorization.

401405865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3822928.

The product of its (nonzero) digits is 19200, while the sum is 33.

The square root of 401405865 is about 20035.1157970200. The cubic root of 401405865 is about 737.6684988931.

Adding to 401405865 its reverse (568504104), we get a palindrome (969909969).

The spelling of 401405865 in words is "four hundred one million, four hundred five thousand, eight hundred sixty-five".