1821664730 has 16 divisors (see below), whose sum is σ = 3286406304. Its totient is φ = 727019280.

The previous prime is 1821664721. The next prime is 1821664781. The reversal of 1821664730 is 374661281.

It is a Curzon 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, 201176 + ... + 210035.

It is an arithmetic number, because the mean of its divisors is an integer number (205400394).

Almost surely, 2^1821664730 is an apocalyptic number.

1821664730 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1821664730 is a deficient number, since it is larger than the sum of its proper divisors (1464741574).

1821664730 is a wasteful number, since it uses less digits than its factorization.

1821664730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 411661.

The product of its (nonzero) digits is 48384, while the sum is 38.

The square root of 1821664730 is about 42680.9644923823. The cubic root of 1821664730 is about 1221.3012922363.

The spelling of 1821664730 in words is "one billion, eight hundred twenty-one million, six hundred sixty-four thousand, seven hundred thirty".