19718957487 has 4 divisors (see below), whose sum is σ = 26291943320. Its totient is φ = 13145971656.

The previous prime is 19718957459. The next prime is 19718957491. The reversal of 19718957487 is 78475981791.

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

It is not a de Polignac number, because 19718957487 - 2¹⁰ = 19718956463 is a prime.

It is a super-2 number, since 2×19718957487² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19718957987) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3286492912 + ... + 3286492917.

It is an arithmetic number, because the mean of its divisors is an integer number (6572985830).

Almost surely, 2^19718957487 is an apocalyptic number.

19718957487 is a deficient number, since it is larger than the sum of its proper divisors (6572985833).

19718957487 is an equidigital number, since it uses as much as digits as its factorization.

19718957487 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6572985832.

The product of its digits is 35562240, while the sum is 66.

The spelling of 19718957487 in words is "nineteen billion, seven hundred eighteen million, nine hundred fifty-seven thousand, four hundred eighty-seven".