401405861 has 4 divisors (see below), whose sum is σ = 401552172. Its totient is φ = 401259552.

The previous prime is 401405857. The next prime is 401405863. The reversal of 401405861 is 168504104.

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

It can be written as a sum of positive squares in 2 ways, for example, as 242393761 + 159012100 = 15569^2 + 12610^2 .

It is a cyclic number.

It is not a de Polignac number, because 401405861 - 2² = 401405857 is a prime.

It is a super-2 number, since 2×401405861² = 322253330490302642, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 68960 + ... + 74553.

It is an arithmetic number, because the mean of its divisors is an integer number (100388043).

Almost surely, 2^401405861 is an apocalyptic number.

It is an amenable number.

401405861 is a deficient number, since it is larger than the sum of its proper divisors (146311).

401405861 is a wasteful number, since it uses less digits than its factorization.

401405861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146310.

The product of its (nonzero) digits is 3840, while the sum is 29.

The square root of 401405861 is about 20035.1156971953. The cubic root of 401405861 is about 737.6684964428.

Adding to 401405861 its reverse (168504104), we get a palindrome (569909965).

The spelling of 401405861 in words is "four hundred one million, four hundred five thousand, eight hundred sixty-one".