1778866812 has 24 divisors (see below), whose sum is σ = 4611877200. Its totient is φ = 592955568.

The previous prime is 1778866807. The next prime is 1778866823. The reversal of 1778866812 is 2186688771.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8235387 + ... + 8235602.

It is an arithmetic number, because the mean of its divisors is an integer number (192161550).

Almost surely, 2^1778866812 is an apocalyptic number.

1778866812 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1778866812 is an abundant number, since it is smaller than the sum of its proper divisors (2833010388).

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

1778866812 is a wasteful number, since it uses less digits than its factorization.

1778866812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16471002 (or 16470994 counting only the distinct ones).

The product of its digits is 1806336, while the sum is 54.

The square root of 1778866812 is about 42176.6145156294. The cubic root of 1778866812 is about 1211.6610413758.

The spelling of 1778866812 in words is "one billion, seven hundred seventy-eight million, eight hundred sixty-six thousand, eight hundred twelve".