19721134 has 4 divisors (see below), whose sum is σ = 29581704. Its totient is φ = 9860566.

The previous prime is 19721129. The next prime is 19721147. The reversal of 19721134 is 43112791.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4930282 + ... + 4930285.

It is an arithmetic number, because the mean of its divisors is an integer number (7395426).

Almost surely, 2^19721134 is an apocalyptic number.

19721134 is a deficient number, since it is larger than the sum of its proper divisors (9860570).

19721134 is an equidigital number, since it uses as much as digits as its factorization.

19721134 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9860569.

The product of its digits is 1512, while the sum is 28.

The square root of 19721134 is about 4440.8483423778. The cubic root of 19721134 is about 270.1742542270.

The spelling of 19721134 in words is "nineteen million, seven hundred twenty-one thousand, one hundred thirty-four".