19713891 has 8 divisors (see below), whose sum is σ = 26540800. Its totient is φ = 13014792.

The previous prime is 19713877. The next prime is 19713899. The reversal of 19713891 is 19831791.

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

It is not a de Polignac number, because 19713891 - 2⁷ = 19713763 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19713899) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31591 + ... + 32208.

It is an arithmetic number, because the mean of its divisors is an integer number (3317600).

Almost surely, 2^19713891 is an apocalyptic number.

19713891 is a deficient number, since it is larger than the sum of its proper divisors (6826909).

19713891 is a wasteful number, since it uses less digits than its factorization.

19713891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63905.

The product of its digits is 13608, while the sum is 39.

The square root of 19713891 is about 4440.0327701493. The cubic root of 19713891 is about 270.1411744568.

The spelling of 19713891 in words is "nineteen million, seven hundred thirteen thousand, eight hundred ninety-one".