1918909440 has 440 divisors, whose sum is σ = 7870502112. Its totient is φ = 437944320.

The previous prime is 1918909423. The next prime is 1918909469. The reversal of 1918909440 is 449098191.

It is a super-2 number, since 2×1918909440² = 7364426877842227200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 2902710 + ... + 2903370.

Almost surely, 2^1918909440 is an apocalyptic number.

1918909440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1918909440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3935251056).

1918909440 is an abundant number, since it is smaller than the sum of its proper divisors (5951592672).

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

1918909440 is an equidigital number, since it uses as much as digits as its factorization.

1918909440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 705 (or 678 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 45.

The square root of 1918909440 is about 43805.3585763203. The cubic root of 1918909440 is about 1242.6576367382.

The spelling of 1918909440 in words is "one billion, nine hundred eighteen million, nine hundred nine thousand, four hundred forty".