19999945 has 32 divisors (see below), whose sum is σ = 28562688. Its totient is φ = 13160448.

The previous prime is 19999927. The next prime is 19999963. The reversal of 19999945 is 54999991.

It is an interprime number because it is at equal distance from previous prime (19999927) and next prime (19999963).

It is not a de Polignac number, because 19999945 - 2⁷ = 19999817 is a prime.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 145917 + ... + 146053.

It is an arithmetic number, because the mean of its divisors is an integer number (892584).

Almost surely, 2^19999945 is an apocalyptic number.

It is an amenable number.

19999945 is a deficient number, since it is larger than the sum of its proper divisors (8562743).

19999945 is a wasteful number, since it uses less digits than its factorization.

19999945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 289.

The product of its digits is 1180980, while the sum is 55.

The square root of 19999945 is about 4472.1298058084. The cubic root of 19999945 is about 271.4415128376.

The spelling of 19999945 in words is "nineteen million, nine hundred ninety-nine thousand, nine hundred forty-five".