1918639128 has 32 divisors (see below), whose sum is σ = 5481826560. Its totient is φ = 548182560.

The previous prime is 1918639117. The next prime is 1918639141. The reversal of 1918639128 is 8219368191.

It is a super-2 number, since 2×1918639128² = 7362352206985200768, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5710068 + ... + 5710403.

It is an arithmetic number, because the mean of its divisors is an integer number (171307080).

Almost surely, 2^1918639128 is an apocalyptic number.

It is an amenable number.

1918639128 is an abundant number, since it is smaller than the sum of its proper divisors (3563187432).

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

1918639128 is a wasteful number, since it uses less digits than its factorization.

1918639128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11420487 (or 11420483 counting only the distinct ones).

The product of its digits is 186624, while the sum is 48.

The square root of 1918639128 is about 43802.2730917015. The cubic root of 1918639128 is about 1242.5992839680.

The spelling of 1918639128 in words is "one billion, nine hundred eighteen million, six hundred thirty-nine thousand, one hundred twenty-eight".