21252708550 has 12 divisors (see below), whose sum is σ = 39530037996. Its totient is φ = 8501083400.

The previous prime is 21252708539. The next prime is 21252708563. The reversal of 21252708550 is 5580725212.

It is a super-2 number, since 2×21252708550² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 212527036 + ... + 212527135.

It is an arithmetic number, because the mean of its divisors is an integer number (3294169833).

Almost surely, 2^21252708550 is an apocalyptic number.

21252708550 is a deficient number, since it is larger than the sum of its proper divisors (18277329446).

21252708550 is a wasteful number, since it uses less digits than its factorization.

21252708550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 425054183 (or 425054178 counting only the distinct ones).

The product of its (nonzero) digits is 56000, while the sum is 37.

The spelling of 21252708550 in words is "twenty-one billion, two hundred fifty-two million, seven hundred eight thousand, five hundred fifty".