19438764981 has 8 divisors (see below), whose sum is σ = 25918997280. Its totient is φ = 12958854672.

The previous prime is 19438764953. The next prime is 19438765009. The reversal of 19438764981 is 18946783491.

It is an interprime number because it is at equal distance from previous prime (19438764953) and next prime (19438765009).

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

It is not a de Polignac number, because 19438764981 - 2⁵ = 19438764949 is a prime.

It is a super-2 number, since 2×19438764981² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19438764911) 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, 200775 + ... + 281403.

It is an arithmetic number, because the mean of its divisors is an integer number (3239874660).

Almost surely, 2^19438764981 is an apocalyptic number.

It is an amenable number.

19438764981 is a deficient number, since it is larger than the sum of its proper divisors (6480232299).

19438764981 is an equidigital number, since it uses as much as digits as its factorization.

19438764981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160995.

The product of its digits is 10450944, while the sum is 60.

The spelling of 19438764981 in words is "nineteen billion, four hundred thirty-eight million, seven hundred sixty-four thousand, nine hundred eighty-one".