402728582881 has 3 divisors (see below), whose sum is σ = 402729217491. Its totient is φ = 402727948272.

The previous prime is 402728582843. The next prime is 402728582909. The reversal of 402728582881 is 188285827204.

The square root of 402728582881 is 634609.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 249409349281 + 153319233600 = 499409^2 + 391560^2 .

It is not a de Polignac number, because 402728582881 - 2¹⁵ = 402728550113 is a prime.

It is a super-2 number, since 2×402728582881² (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 (402728582681) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 317305 + ... + 951913.

It is an arithmetic number, because the mean of its divisors is an integer number (134243072497).

Almost surely, 2^402728582881 is an apocalyptic number.

402728582881 is the 634609-th square number.

402728582881 is the 317305-th centered octagonal number.

It is an amenable number.

402728582881 is a deficient number, since it is larger than the sum of its proper divisors (634610).

402728582881 is an frugal number, since it uses more digits than its factorization.

402728582881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1269218 (or 634609 counting only the distinct ones).

The product of its (nonzero) digits is 4587520, while the sum is 55.

The spelling of 402728582881 in words is "four hundred two billion, seven hundred twenty-eight million, five hundred eighty-two thousand, eight hundred eighty-one".