19730711891 has 8 divisors (see below), whose sum is σ = 21546144768. Its totient is φ = 17918901000.

The previous prime is 19730711881. The next prime is 19730711893. The reversal of 19730711891 is 19811703791.

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

It is not a de Polignac number, because 19730711891 - 2¹⁴ = 19730695507 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19730711893) 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, 894095 + ... + 915896.

It is an arithmetic number, because the mean of its divisors is an integer number (2693268096).

Almost surely, 2^19730711891 is an apocalyptic number.

19730711891 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

19730711891 is a deficient number, since it is larger than the sum of its proper divisors (1815432877).

19730711891 is a wasteful number, since it uses less digits than its factorization.

19730711891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1810993.

The product of its (nonzero) digits is 95256, while the sum is 47.

The spelling of 19730711891 in words is "nineteen billion, seven hundred thirty million, seven hundred eleven thousand, eight hundred ninety-one".