21650521600 has 120 divisors (see below), whose sum is σ = 54175191048. Its totient is φ = 8573952000.

The previous prime is 21650521597. The next prime is 21650521637. The reversal of 21650521600 is 612505612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1284427 + ... + 1301173.

Almost surely, 2^21650521600 is an apocalyptic number.

21650521600 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21650521600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27087595524).

21650521600 is an abundant number, since it is smaller than the sum of its proper divisors (32524669448).

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

21650521600 is a wasteful number, since it uses less digits than its factorization.

21650521600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16876 (or 16855 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 28.

The spelling of 21650521600 in words is "twenty-one billion, six hundred fifty million, five hundred twenty-one thousand, six hundred".