21133919550 has 48 divisors (see below), whose sum is σ = 52616154672. Its totient is φ = 5613772800.

The previous prime is 21133919533. The next prime is 21133919591. The reversal of 21133919550 is 5591933112.

It is a junction number, because it is equal to n+sod(n) for n = 21133919499 and 21133919508.

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 23 ways as a sum of consecutive naturals, for example, 235561 + ... + 312660.

It is an arithmetic number, because the mean of its divisors is an integer number (1096169889).

Almost surely, 2^21133919550 is an apocalyptic number.

21133919550 is an abundant number, since it is smaller than the sum of its proper divisors (31482235122).

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

21133919550 is a wasteful number, since it uses less digits than its factorization.

21133919550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 548493 (or 548488 counting only the distinct ones).

The product of its (nonzero) digits is 36450, while the sum is 39.

The spelling of 21133919550 in words is "twenty-one billion, one hundred thirty-three million, nine hundred nineteen thousand, five hundred fifty".