402809816929 has 9 divisors (see below), whose sum is σ = 436187611929. Its totient is φ = 371816830320.

The previous prime is 402809816917. The next prime is 402809816963. The reversal of 402809816929 is 929618908204.

The square root of 402809816929 is 634673.

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

It can be written as a sum of positive squares in 4 ways, for example, as 4709390625 + 398100426304 = 68625^2 + 630952^2 .

It is not a de Polignac number, because 402809816929 - 2²⁹ = 402272946017 is a prime.

It is a super-2 number, since 2×402809816929² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (402809816999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 8226339 + ... + 8275159.

Almost surely, 2^402809816929 is an apocalyptic number.

402809816929 is the 634673-rd square number.

402809816929 is the 317337-th centered octagonal number.

It is an amenable number.

402809816929 is a deficient number, since it is larger than the sum of its proper divisors (33377795000).

402809816929 is an frugal number, since it uses more digits than its factorization.

402809816929 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97668 (or 48834 counting only the distinct ones).

The product of its (nonzero) digits is 4478976, while the sum is 58.

The spelling of 402809816929 in words is "four hundred two billion, eight hundred nine million, eight hundred sixteen thousand, nine hundred twenty-nine".