1638402 has 8 divisors (see below), whose sum is σ = 3276816. Its totient is φ = 546132.

The previous prime is 1638353. The next prime is 1638431. The reversal of 1638402 is 2048361.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

1638402 is an admirable number.

It is a super-2 number, since 2×1638402² = 5368722227208, which contains 22 as substring.

It is a plaindrome in base 15.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 136528 + ... + 136539.

It is an arithmetic number, because the mean of its divisors is an integer number (409602).

2^1638402 is an apocalyptic number.

1638402 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

1638402 is a wasteful number, since it uses less digits than its factorization.

1638402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 273072.

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 1638402 is about 1280.0007812498. Note that the first 3 decimals coincide. The cubic root of 1638402 is about 117.8890559256.

The spelling of 1638402 in words is "one million, six hundred thirty-eight thousand, four hundred two".