21869085924 has 135 divisors (see below), whose sum is σ = 64618182083. Its totient is φ = 6235888176.

The previous prime is 21869085913. The next prime is 21869085971. The reversal of 21869085924 is 42958096812.

It is a happy number.

The square root of 21869085924 is 147882.

It is a perfect power (a square), and thus also a powerful number.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 43477057 + ... + 43477559.

Almost surely, 2^21869085924 is an apocalyptic number.

21869085924 is the 147882-nd square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21869085924

21869085924 is an abundant number, since it is smaller than the sum of its proper divisors (42749096159).

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

21869085924 is an frugal number, since it uses more digits than its factorization.

21869085924 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1044 (or 515 counting only the distinct ones).

The product of its (nonzero) digits is 2488320, while the sum is 54.

The spelling of 21869085924 in words is "twenty-one billion, eight hundred sixty-nine million, eighty-five thousand, nine hundred twenty-four".