1999664755 has 24 divisors (see below), whose sum is σ = 2643933600. Its totient is φ = 1450796160.

The previous prime is 1999664749. The next prime is 1999664789. The reversal of 1999664755 is 5574669991.

It is not a de Polignac number, because 1999664755 - 2⁹ = 1999664243 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1999664693 and 1999664702.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 261831 + ... + 269359.

It is an arithmetic number, because the mean of its divisors is an integer number (110163900).

Almost surely, 2^1999664755 is an apocalyptic number.

1999664755 is a deficient number, since it is larger than the sum of its proper divisors (644268845).

1999664755 is a wasteful number, since it uses less digits than its factorization.

1999664755 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7995 (or 7984 counting only the distinct ones).

The product of its digits is 18370800, while the sum is 61.

The square root of 1999664755 is about 44717.6112398683. The cubic root of 1999664755 is about 1259.8506489224.

The spelling of 1999664755 in words is "one billion, nine hundred ninety-nine million, six hundred sixty-four thousand, seven hundred fifty-five".