402809472 has 144 divisors (see below), whose sum is σ = 1255755150. Its totient is φ = 123881472.

The previous prime is 402809471. The next prime is 402809479. The reversal of 402809472 is 274908204.

It can be written as a sum of positive squares in 3 ways, for example, as 127780416 + 275029056 = 11304^2 + 16584^2 .

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (402809471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 193654 + ... + 195722.

Almost surely, 2^402809472 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 402809472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (627877575).

402809472 is an abundant number, since it is smaller than the sum of its proper divisors (852945678).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

402809472 is a wasteful number, since it uses less digits than its factorization.

402809472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2115 (or 2087 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The square root of 402809472 is about 20070.1139010221. The cubic root of 402809472 is about 738.5273072834.

The spelling of 402809472 in words is "four hundred two million, eight hundred nine thousand, four hundred seventy-two".