19991002 has 32 divisors (see below), whose sum is σ = 33436800. Its totient is φ = 8921088.

The previous prime is 19990937. The next prime is 19991003. The reversal of 19991002 is 20019991.

It is not an unprimeable number, because it can be changed into a prime (19991003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 77658 + ... + 77914.

It is an arithmetic number, because the mean of its divisors is an integer number (1044900).

Almost surely, 2^19991002 is an apocalyptic number.

19991002 is a deficient number, since it is larger than the sum of its proper divisors (13445798).

19991002 is a wasteful number, since it uses less digits than its factorization.

19991002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390.

The product of its (nonzero) digits is 1458, while the sum is 31.

The square root of 19991002 is about 4471.1298348404. The cubic root of 19991002 is about 271.4010483370.

The spelling of 19991002 in words is "nineteen million, nine hundred ninety-one thousand, two".