19130821 has 8 divisors (see below), whose sum is σ = 19367744. Its totient is φ = 18895680.

The previous prime is 19130803. The next prime is 19130843. The reversal of 19130821 is 12803191.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a 10-Lehmer number, since φ(19130821) divides (19130821-1)¹⁰.

It is a cyclic number.

It is not a de Polignac number, because 19130821 - 2⁷ = 19130693 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 (19130801) 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 7 ways as a sum of consecutive naturals, for example, 39040 + ... + 39526.

It is an arithmetic number, because the mean of its divisors is an integer number (2420968).

Almost surely, 2^19130821 is an apocalyptic number.

It is an amenable number.

19130821 is a deficient number, since it is larger than the sum of its proper divisors (236923).

19130821 is a wasteful number, since it uses less digits than its factorization.

19130821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 891.

The product of its (nonzero) digits is 432, while the sum is 25.

The square root of 19130821 is about 4373.8793993433. The cubic root of 19130821 is about 267.4511909083.

The spelling of 19130821 in words is "nineteen million, one hundred thirty thousand, eight hundred twenty-one".