402638889 has 16 divisors (see below), whose sum is σ = 541900800. Its totient is φ = 265914000.

The previous prime is 402638879. The next prime is 402638909. The reversal of 402638889 is 988836204.

It is a happy number.

It is not a de Polignac number, because 402638889 - 2⁹ = 402638377 is a prime.

It is not an unprimeable number, because it can be changed into a prime (402638839) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 148504 + ... + 151190.

It is an arithmetic number, because the mean of its divisors is an integer number (33868800).

Almost surely, 2^402638889 is an apocalyptic number.

It is an amenable number.

402638889 is a deficient number, since it is larger than the sum of its proper divisors (139261911).

402638889 is a wasteful number, since it uses less digits than its factorization.

402638889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3140.

The product of its (nonzero) digits is 663552, while the sum is 48.

The square root of 402638889 is about 20065.8637740816. The cubic root of 402638889 is about 738.4230412882.

The spelling of 402638889 in words is "four hundred two million, six hundred thirty-eight thousand, eight hundred eighty-nine".