19778402499 has 16 divisors (see below), whose sum is σ = 26835494400. Its totient is φ = 12953745056.

The previous prime is 19778402477. The next prime is 19778402509. The reversal of 19778402499 is 99420487791.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19778402499 is a prime.

It is not an unprimeable number, because it can be changed into a prime (19778402999) 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 in 15 ways as a sum of consecutive naturals, for example, 244897 + ... + 315485.

It is an arithmetic number, because the mean of its divisors is an integer number (1677218400).

Almost surely, 2^19778402499 is an apocalyptic number.

19778402499 is a deficient number, since it is larger than the sum of its proper divisors (7057091901).

19778402499 is a wasteful number, since it uses less digits than its factorization.

19778402499 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72234.

The product of its (nonzero) digits is 9144576, while the sum is 60.

The spelling of 19778402499 in words is "nineteen billion, seven hundred seventy-eight million, four hundred two thousand, four hundred ninety-nine".