402638838 has 32 divisors (see below), whose sum is σ = 923080704. Its totient is φ = 114694272.

The previous prime is 402638807. The next prime is 402638839. The reversal of 402638838 is 838836204.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a self number, because there is not a number n which added to its sum of digits gives 402638838.

It is a congruent number.

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

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 70 + ... + 28377.

It is an arithmetic number, because the mean of its divisors is an integer number (28846272).

Almost surely, 2^402638838 is an apocalyptic number.

402638838 is an abundant number, since it is smaller than the sum of its proper divisors (520441866).

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

402638838 is a wasteful number, since it uses less digits than its factorization.

402638838 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28796.

The product of its (nonzero) digits is 221184, while the sum is 42.

The square root of 402638838 is about 20065.8625032666. The cubic root of 402638838 is about 738.4230101109.

The spelling of 402638838 in words is "four hundred two million, six hundred thirty-eight thousand, eight hundred thirty-eight".