21650513550 has 48 divisors (see below), whose sum is σ = 53862771312. Its totient is φ = 5755244800.

The previous prime is 21650513539. The next prime is 21650513561. The reversal of 21650513550 is 5531505612.

It is an interprime number because it is at equal distance from previous prime (21650513539) and next prime (21650513561).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 180111 + ... + 275210.

It is an arithmetic number, because the mean of its divisors is an integer number (1122141069).

Almost surely, 2^21650513550 is an apocalyptic number.

21650513550 is an abundant number, since it is smaller than the sum of its proper divisors (32212257762).

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

21650513550 is a wasteful number, since it uses less digits than its factorization.

21650513550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 455653 (or 455648 counting only the distinct ones).

The product of its (nonzero) digits is 22500, while the sum is 33.

The spelling of 21650513550 in words is "twenty-one billion, six hundred fifty million, five hundred thirteen thousand, five hundred fifty".