402691645 has 4 divisors (see below), whose sum is σ = 483229980. Its totient is φ = 322153312.

The previous prime is 402691591. The next prime is 402691657. The reversal of 402691645 is 546196204.

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 214974244 + 187717401 = 14662^2 + 13701^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-402691645 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40269160 + ... + 40269169.

It is an arithmetic number, because the mean of its divisors is an integer number (120807495).

Almost surely, 2^402691645 is an apocalyptic number.

It is an amenable number.

402691645 is a deficient number, since it is larger than the sum of its proper divisors (80538335).

402691645 is an equidigital number, since it uses as much as digits as its factorization.

402691645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80538334.

The product of its (nonzero) digits is 51840, while the sum is 37.

The square root of 402691645 is about 20067.1783018939. The cubic root of 402691645 is about 738.4552906525.

It can be divided in two parts, 40269 and 1645, that added together give a palindrome (41914).

The spelling of 402691645 in words is "four hundred two million, six hundred ninety-one thousand, six hundred forty-five".