19957795949 has 32 divisors (see below), whose sum is σ = 26024334336. Its totient is φ = 14852782080.

The previous prime is 19957795943. The next prime is 19957795987. The reversal of 19957795949 is 94959775991.

It is a cyclic number.

It is not a de Polignac number, because 19957795949 - 2¹⁶ = 19957730413 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19957795943) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3535169 + ... + 3540809.

It is an arithmetic number, because the mean of its divisors is an integer number (813260448).

Almost surely, 2^19957795949 is an apocalyptic number.

It is an amenable number.

19957795949 is a deficient number, since it is larger than the sum of its proper divisors (6066538387).

19957795949 is a wasteful number, since it uses less digits than its factorization.

19957795949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7965.

The product of its digits is 289340100, while the sum is 74.

The spelling of 19957795949 in words is "nineteen billion, nine hundred fifty-seven million, seven hundred ninety-five thousand, nine hundred forty-nine".