19965640274 has 4 divisors (see below), whose sum is σ = 29948460414. Its totient is φ = 9982820136.

The previous prime is 19965640273. The next prime is 19965640309. The reversal of 19965640274 is 47204656991.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 16296309649 + 3669330625 = 127657^2 + 60575^2 .

It is not an unprimeable number, because it can be changed into a prime (19965640273) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4991410067 + ... + 4991410070.

Almost surely, 2^19965640274 is an apocalyptic number.

19965640274 is a deficient number, since it is larger than the sum of its proper divisors (9982820140).

19965640274 is an equidigital number, since it uses as much as digits as its factorization.

19965640274 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9982820139.

The product of its (nonzero) digits is 3265920, while the sum is 53.

The spelling of 19965640274 in words is "nineteen billion, nine hundred sixty-five million, six hundred forty thousand, two hundred seventy-four".