1891064718 has 80 divisors (see below), whose sum is σ = 4500706320. Its totient is φ = 591784704.

The previous prime is 1891064701. The next prime is 1891064729. The reversal of 1891064718 is 8174601981.

It is a happy number.

It is a super-2 number, since 2×1891064718² = 7152251535328839048, which contains 22 as substring.

It is a Curzon number.

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, 345096 + ... + 350532.

It is an arithmetic number, because the mean of its divisors is an integer number (56258829).

Almost surely, 2^1891064718 is an apocalyptic number.

1891064718 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1891064718, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2250353160).

1891064718 is an abundant number, since it is smaller than the sum of its proper divisors (2609641602).

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

1891064718 is a wasteful number, since it uses less digits than its factorization.

1891064718 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5583 (or 5574 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 45.

The square root of 1891064718 is about 43486.3739348316. The cubic root of 1891064718 is about 1236.6177160228.

The spelling of 1891064718 in words is "one billion, eight hundred ninety-one million, sixty-four thousand, seven hundred eighteen".