21550391250 has 40 divisors (see below), whose sum is σ = 53858747184. Its totient is φ = 5746770000.

The previous prime is 21550391249. The next prime is 21550391263. The reversal of 21550391250 is 5219305512.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2869636 + ... + 2877135.

Almost surely, 2^21550391250 is an apocalyptic number.

21550391250 is an abundant number, since it is smaller than the sum of its proper divisors (32308355934).

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

21550391250 is an equidigital number, since it uses as much as digits as its factorization.

21550391250 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5746796 (or 5746781 counting only the distinct ones).

The product of its (nonzero) digits is 13500, while the sum is 33.

Adding to 21550391250 its reverse (5219305512), we get a palindrome (26769696762).

The spelling of 21550391250 in words is "twenty-one billion, five hundred fifty million, three hundred ninety-one thousand, two hundred fifty".