19999953 has 10 divisors (see below), whose sum is σ = 29876594. Its totient is φ = 13333248.

The previous prime is 19999927. The next prime is 19999963. The reversal of 19999953 is 35999991.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 17740944 + 2259009 = 4212^2 + 1503^2 .

It is not a de Polignac number, because 19999953 - 2⁸ = 19999697 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 19999953.

It is not an unprimeable number, because it can be changed into a prime (19999963) 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 9 ways as a sum of consecutive naturals, for example, 123376 + ... + 123537.

Almost surely, 2^19999953 is an apocalyptic number.

It is an amenable number.

19999953 is a deficient number, since it is larger than the sum of its proper divisors (9876641).

19999953 is an equidigital number, since it uses as much as digits as its factorization.

19999953 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 246925 (or 246916 counting only the distinct ones).

The product of its digits is 885735, while the sum is 54.

The square root of 19999953 is about 4472.1307002367. The cubic root of 19999953 is about 271.4415490299.

The spelling of 19999953 in words is "nineteen million, nine hundred ninety-nine thousand, nine hundred fifty-three".