1809736668 has 42 divisors (see below), whose sum is σ = 4748394224. Its totient is φ = 603244584.

The previous prime is 1809736633. The next prime is 1809736699. The reversal of 1809736668 is 8666379081.

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 13 ways as a sum of consecutive naturals, for example, 307396 + ... + 313227.

Almost surely, 2^1809736668 is an apocalyptic number.

1809736668 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1809736668 is an abundant number, since it is smaller than the sum of its proper divisors (2938657556).

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

1809736668 is an equidigital number, since it uses as much as digits as its factorization.

1809736668 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 620645 (or 620628 counting only the distinct ones).

The product of its (nonzero) digits is 2612736, while the sum is 54.

The square root of 1809736668 is about 42540.9998472062. Note that the first 3 decimals coincide. The cubic root of 1809736668 is about 1218.6298036256.

The spelling of 1809736668 in words is "one billion, eight hundred nine million, seven hundred thirty-six thousand, six hundred sixty-eight".