21255562350 has 384 divisors, whose sum is σ = 66415749120. Its totient is φ = 5015520000.

The previous prime is 21255562291. The next prime is 21255562387. The reversal of 21255562350 is 5326555212.

21255562350 is a `hidden beast` number, since 2 + 1 + 25 + 5 + 5 + 623 + 5 + 0 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 49316635 + ... + 49317065.

It is an arithmetic number, because the mean of its divisors is an integer number (172957680).

Almost surely, 2^21255562350 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21255562350, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33207874560).

21255562350 is an abundant number, since it is smaller than the sum of its proper divisors (45160186770).

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

21255562350 is a wasteful number, since it uses less digits than its factorization.

21255562350 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 516 (or 493 counting only the distinct ones).

The product of its (nonzero) digits is 90000, while the sum is 36.

The spelling of 21255562350 in words is "twenty-one billion, two hundred fifty-five million, five hundred sixty-two thousand, three hundred fifty".