21373686587 has 16 divisors (see below), whose sum is σ = 24668582400. Its totient is φ = 18314483040.

The previous prime is 21373686547. The next prime is 21373686619. The reversal of 21373686587 is 78568637312.

It is not a de Polignac number, because 21373686587 - 2¹⁴ = 21373670203 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21373686527) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 218387 + ... + 300732.

It is an arithmetic number, because the mean of its divisors is an integer number (1541786400).

Almost surely, 2^21373686587 is an apocalyptic number.

21373686587 is a deficient number, since it is larger than the sum of its proper divisors (3294895813).

21373686587 is a wasteful number, since it uses less digits than its factorization.

21373686587 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 519346.

The product of its digits is 10160640, while the sum is 56.

The spelling of 21373686587 in words is "twenty-one billion, three hundred seventy-three million, six hundred eighty-six thousand, five hundred eighty-seven".