21780122650 has 96 divisors (see below), whose sum is σ = 47656324800. Its totient is φ = 7301145600.

The previous prime is 21780122627. The next prime is 21780122681. The reversal of 21780122650 is 5622108712.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 7212841 + ... + 7215859.

It is an arithmetic number, because the mean of its divisors is an integer number (496420050).

Almost surely, 2^21780122650 is an apocalyptic number.

21780122650 is an abundant number, since it is smaller than the sum of its proper divisors (25876202150).

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

21780122650 is a wasteful number, since it uses less digits than its factorization.

21780122650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4064 (or 4059 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 34.

The spelling of 21780122650 in words is "twenty-one billion, seven hundred eighty million, one hundred twenty-two thousand, six hundred fifty".