21587278512 has 160 divisors (see below), whose sum is σ = 57484410048. Its totient is φ = 6978797568.

The previous prime is 21587278501. The next prime is 21587278597.

21587278512 is nontrivially palindromic in base 10.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 92649148 + ... + 92649380.

Almost surely, 2^21587278512 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21587278512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28742205024).

21587278512 is an abundant number, since it is smaller than the sum of its proper divisors (35897131536).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21587278512 is a wasteful number, since it uses less digits than its factorization.

21587278512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 647 (or 641 counting only the distinct ones).

The product of its digits is 627200, while the sum is 48.

The spelling of 21587278512 in words is "twenty-one billion, five hundred eighty-seven million, two hundred seventy-eight thousand, five hundred twelve".