19891553 has 12 divisors (see below), whose sum is σ = 22573824. Its totient is φ = 17496600.

The previous prime is 19891549. The next prime is 19891559. The reversal of 19891553 is 35519891.

It is not a de Polignac number, because 19891553 - 2² = 19891549 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 19891553.

It is not an unprimeable number, because it can be changed into a prime (19891559) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1100 + ... + 6402.

It is an arithmetic number, because the mean of its divisors is an integer number (1881152).

Almost surely, 2^19891553 is an apocalyptic number.

It is an amenable number.

19891553 is a deficient number, since it is larger than the sum of its proper divisors (2682271).

19891553 is a wasteful number, since it uses less digits than its factorization.

19891553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5356 (or 5345 counting only the distinct ones).

The product of its digits is 48600, while the sum is 41.

The square root of 19891553 is about 4459.9947309386. The cubic root of 19891553 is about 270.9502547999.

The spelling of 19891553 in words is "nineteen million, eight hundred ninety-one thousand, five hundred fifty-three".