402100805 has 16 divisors (see below), whose sum is σ = 499791600. Its totient is φ = 310195200.

The previous prime is 402100723. The next prime is 402100807. The reversal of 402100805 is 508001204.

It can be written as a sum of positive squares in 8 ways, for example, as 24226084 + 377874721 = 4922^2 + 19439^2 .

It is not a de Polignac number, because 402100805 - 2⁸ = 402100549 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (402100807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 172991 + ... + 175299.

It is an arithmetic number, because the mean of its divisors is an integer number (31236975).

Almost surely, 2^402100805 is an apocalyptic number.

It is an amenable number.

402100805 is a deficient number, since it is larger than the sum of its proper divisors (97690795).

402100805 is a wasteful number, since it uses less digits than its factorization.

402100805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3544.

The product of its (nonzero) digits is 320, while the sum is 20.

The square root of 402100805 is about 20052.4513464065. The cubic root of 402100805 is about 738.0939533932.

The spelling of 402100805 in words is "four hundred two million, one hundred thousand, eight hundred five".