1918809816 has 96 divisors (see below), whose sum is σ = 6087545280. Its totient is φ = 498388800.

The previous prime is 1918809787. The next prime is 1918809877. The reversal of 1918809816 is 6189088191.

It is a super-2 number, since 2×1918809816² = 7363662219955907712, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 61230 + ... + 87101.

It is an arithmetic number, because the mean of its divisors is an integer number (63411930).

Almost surely, 2^1918809816 is an apocalyptic number.

It is an amenable number.

1918809816 is an abundant number, since it is smaller than the sum of its proper divisors (4168735464).

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

1918809816 is a wasteful number, since it uses less digits than its factorization.

1918809816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148365 (or 148354 counting only the distinct ones).

The product of its (nonzero) digits is 248832, while the sum is 51.

The square root of 1918809816 is about 43804.2214404046. The cubic root of 1918809816 is about 1242.6361313518.

The spelling of 1918809816 in words is "one billion, nine hundred eighteen million, eight hundred nine thousand, eight hundred sixteen".