21785050 has 48 divisors (see below), whose sum is σ = 47050560. Its totient is φ = 7349760.

The previous prime is 21785009. The next prime is 21785051. The reversal of 21785050 is 5058712.

It is not an unprimeable number, because it can be changed into a prime (21785051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 22986 + ... + 23914.

It is an arithmetic number, because the mean of its divisors is an integer number (980220).

Almost surely, 2^21785050 is an apocalyptic number.

21785050 is an abundant number, since it is smaller than the sum of its proper divisors (25265510).

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

21785050 is a wasteful number, since it uses less digits than its factorization.

21785050 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1015 (or 1010 counting only the distinct ones).

The product of its (nonzero) digits is 2800, while the sum is 28.

The square root of 21785050 is about 4667.4457682977. The cubic root of 21785050 is about 279.2883714781.

It can be divided in two parts, 217 and 85050, that multiplied together give a triangular number (18455850 = T₆₀₇₅).

The spelling of 21785050 in words is "twenty-one million, seven hundred eighty-five thousand, fifty".