19979227749 has 16 divisors (see below), whose sum is σ = 28726363904. Its totient is φ = 12278520000.

The previous prime is 19979227711. The next prime is 19979227753. The reversal of 19979227749 is 94772297991.

It is a happy number.

It is not a de Polignac number, because 19979227749 - 2⁸ = 19979227493 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 19979227749.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19979227769) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 311782 + ... + 370359.

It is an arithmetic number, because the mean of its divisors is an integer number (1795397744).

Almost surely, 2^19979227749 is an apocalyptic number.

It is an amenable number.

19979227749 is a deficient number, since it is larger than the sum of its proper divisors (8747136155).

19979227749 is a wasteful number, since it uses less digits than its factorization.

19979227749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 682908.

The product of its digits is 36006768, while the sum is 66.

The spelling of 19979227749 in words is "nineteen billion, nine hundred seventy-nine million, two hundred twenty-seven thousand, seven hundred forty-nine".