19867402587 has 4 divisors (see below), whose sum is σ = 26489870120. Its totient is φ = 13244935056.

The previous prime is 19867402579. The next prime is 19867402589. The reversal of 19867402587 is 78520476891.

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

It is not a de Polignac number, because 19867402587 - 2³ = 19867402579 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19867402589) 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, 3311233762 + ... + 3311233767.

It is an arithmetic number, because the mean of its divisors is an integer number (6622467530).

Almost surely, 2^19867402587 is an apocalyptic number.

19867402587 is a deficient number, since it is larger than the sum of its proper divisors (6622467533).

19867402587 is an equidigital number, since it uses as much as digits as its factorization.

19867402587 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6622467532.

The product of its (nonzero) digits is 6773760, while the sum is 57.

The spelling of 19867402587 in words is "nineteen billion, eight hundred sixty-seven million, four hundred two thousand, five hundred eighty-seven".