19890613 has 4 divisors (see below), whose sum is σ = 20047360. Its totient is φ = 19733868.

The previous prime is 19890593. The next prime is 19890631. The reversal of 19890613 is 31609891.

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, and also an emirpimes, since its reverse is a distinct semiprime: 31609891 = 109 ⋅289999.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19890613 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 (19890643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 78183 + ... + 78436.

It is an arithmetic number, because the mean of its divisors is an integer number (5011840).

Almost surely, 2^19890613 is an apocalyptic number.

It is an amenable number.

19890613 is a deficient number, since it is larger than the sum of its proper divisors (156747).

19890613 is a wasteful number, since it uses less digits than its factorization.

19890613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156746.

The product of its (nonzero) digits is 11664, while the sum is 37.

The square root of 19890613 is about 4459.8893484032. The cubic root of 19890613 is about 270.9459867026.

It can be divided in two parts, 19890 and 613, that added together give a triangular number (20503 = T₂₀₂).

The spelling of 19890613 in words is "nineteen million, eight hundred ninety thousand, six hundred thirteen".