19899613 has 4 divisors (see below), whose sum is σ = 20541568. Its totient is φ = 19257660.

The previous prime is 19899589. The next prime is 19899629. The reversal of 19899613 is 31699891.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19899613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19899653) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 320931 + ... + 320992.

It is an arithmetic number, because the mean of its divisors is an integer number (5135392).

Almost surely, 2^19899613 is an apocalyptic number.

It is an amenable number.

19899613 is a deficient number, since it is larger than the sum of its proper divisors (641955).

19899613 is an equidigital number, since it uses as much as digits as its factorization.

19899613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 641954.

The product of its digits is 104976, while the sum is 46.

The square root of 19899613 is about 4460.8982279357. The cubic root of 19899613 is about 270.9868459459.

The spelling of 19899613 in words is "nineteen million, eight hundred ninety-nine thousand, six hundred thirteen".