1999999928 has 8 divisors (see below), whose sum is σ = 3749999880. Its totient is φ = 999999960.

The previous prime is 1999999927. The next prime is 1999999943. The reversal of 1999999928 is 8299999991.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1999999927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 124999988 + ... + 125000003.

It is an arithmetic number, because the mean of its divisors is an integer number (468749985).

Almost surely, 2^1999999928 is an apocalyptic number.

It is an amenable number.

1999999928 is a deficient number, since it is larger than the sum of its proper divisors (1749999952).

1999999928 is a wasteful number, since it uses less digits than its factorization.

1999999928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 249999997 (or 249999993 counting only the distinct ones).

The product of its digits is 76527504, while the sum is 74.

The square root of 1999999928 is about 44721.3587450113. The cubic root of 1999999928 is about 1259.9210347758.

Adding to 1999999928 its sum of digits (74), we get a palindrome (2000000002).

The spelling of 1999999928 in words is "one billion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred twenty-eight".