21258971874 has 96 divisors (see below), whose sum is σ = 53132526720. Its totient is φ = 6017573376.

The previous prime is 21258971837. The next prime is 21258971891. The reversal of 21258971874 is 47817985212.

It is a self number, because there is not a number n which added to its sum of digits gives 21258971874.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6606714 + ... + 6609930.

It is an arithmetic number, because the mean of its divisors is an integer number (553463820).

Almost surely, 2^21258971874 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21258971874, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26566263360).

21258971874 is an abundant number, since it is smaller than the sum of its proper divisors (31873554846).

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

21258971874 is a wasteful number, since it uses less digits than its factorization.

21258971874 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3704 (or 3701 counting only the distinct ones).

The product of its digits is 2257920, while the sum is 54.

The spelling of 21258971874 in words is "twenty-one billion, two hundred fifty-eight million, nine hundred seventy-one thousand, eight hundred seventy-four".