19439139756 has 72 divisors (see below), whose sum is σ = 47083667904. Its totient is φ = 6241941440.

The previous prime is 19439139751. The next prime is 19439139763. The reversal of 19439139756 is 65793193491.

It is a junction number, because it is equal to n+sod(n) for n = 19439139696 and 19439139705.

It is not an unprimeable number, because it can be changed into a prime (19439139751) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4953211 + ... + 4957133.

It is an arithmetic number, because the mean of its divisors is an integer number (653939832).

Almost surely, 2^19439139756 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19439139756, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23541833952).

19439139756 is an abundant number, since it is smaller than the sum of its proper divisors (27644528148).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

19439139756 is a wasteful number, since it uses less digits than its factorization.

19439139756 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4479 (or 4448 counting only the distinct ones).

The product of its digits is 5511240, while the sum is 57.

The spelling of 19439139756 in words is "nineteen billion, four hundred thirty-nine million, one hundred thirty-nine thousand, seven hundred fifty-six".