400865851 has 4 divisors (see below), whose sum is σ = 402021432. Its totient is φ = 399710272.

The previous prime is 400865809. The next prime is 400865887. The reversal of 400865851 is 158568004.

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 400865851 - 2⁷ = 400865723 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 400865851.

It is not an unprimeable number, because it can be changed into a prime (400865051) 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, 577270 + ... + 577963.

It is an arithmetic number, because the mean of its divisors is an integer number (100505358).

Almost surely, 2^400865851 is an apocalyptic number.

400865851 is a deficient number, since it is larger than the sum of its proper divisors (1155581).

400865851 is a wasteful number, since it uses less digits than its factorization.

400865851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1155580.

The product of its (nonzero) digits is 38400, while the sum is 37.

The square root of 400865851 is about 20021.6345736306. The cubic root of 400865851 is about 737.3375536495.

The spelling of 400865851 in words is "four hundred million, eight hundred sixty-five thousand, eight hundred fifty-one".