402840281809 has 15 divisors (see below), whose sum is σ = 469988649563. Its totient is φ = 345265012848.

The previous prime is 402840281797. The next prime is 402840281861. The reversal of 402840281809 is 908182048204.

The square root of 402840281809 is 634697.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 37937300625 + 364902981184 = 194775^2 + 604072^2 .

It is not a de Polignac number, because 402840281809 - 2²⁹ = 402303410897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (402840281209) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 31093677 + ... + 31106629.

Almost surely, 2^402840281809 is an apocalyptic number.

402840281809 is a gapful number since it is divisible by the number (49) formed by its first and last digit.

402840281809 is the 634697-th square number.

402840281809 is the 317349-th centered octagonal number.

It is an amenable number.

402840281809 is a deficient number, since it is larger than the sum of its proper divisors (67148367754).

402840281809 is an frugal number, since it uses more digits than its factorization.

402840281809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25934 (or 12960 counting only the distinct ones).

The product of its (nonzero) digits is 294912, while the sum is 46.

The spelling of 402840281809 in words is "four hundred two billion, eight hundred forty million, two hundred eighty-one thousand, eight hundred nine".