21508252050 has 24 divisors (see below), whose sum is σ = 53340465456. Its totient is φ = 5735533840.

The previous prime is 21508252021. The next prime is 21508252067. The reversal of 21508252050 is 5025280512.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 21508251999 and 21508252017.

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 11 ways as a sum of consecutive naturals, for example, 71694024 + ... + 71694323.

It is an arithmetic number, because the mean of its divisors is an integer number (2222519394).

Almost surely, 2^21508252050 is an apocalyptic number.

21508252050 is an abundant number, since it is smaller than the sum of its proper divisors (31832213406).

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

21508252050 is a wasteful number, since it uses less digits than its factorization.

21508252050 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143388362 (or 143388357 counting only the distinct ones).

The product of its (nonzero) digits is 8000, while the sum is 30.

The spelling of 21508252050 in words is "twenty-one billion, five hundred eight million, two hundred fifty-two thousand, fifty".