21555752450 has 24 divisors (see below), whose sum is σ = 40482968448. Its totient is φ = 8538587280.

The previous prime is 21555752431. The next prime is 21555752507. The reversal of 21555752450 is 5425755512.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21555752398 and 21555752407.

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 11 ways as a sum of consecutive naturals, for example, 2087642 + ... + 2097941.

It is an arithmetic number, because the mean of its divisors is an integer number (1686790352).

Almost surely, 2^21555752450 is an apocalyptic number.

21555752450 is a deficient number, since it is larger than the sum of its proper divisors (18927215998).

21555752450 is a wasteful number, since it uses less digits than its factorization.

21555752450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4185698 (or 4185693 counting only the distinct ones).

The product of its (nonzero) digits is 350000, while the sum is 41.

The spelling of 21555752450 in words is "twenty-one billion, five hundred fifty-five million, seven hundred fifty-two thousand, four hundred fifty".