21857950 has 12 divisors (see below), whose sum is σ = 40655880. Its totient is φ = 8743160.

The previous prime is 21857933. The next prime is 21857951. The reversal of 21857950 is 5975812.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21857951) 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 5 ways as a sum of consecutive naturals, for example, 218530 + ... + 218629.

It is an arithmetic number, because the mean of its divisors is an integer number (3387990).

Almost surely, 2^21857950 is an apocalyptic number.

21857950 is a deficient number, since it is larger than the sum of its proper divisors (18797930).

21857950 is a wasteful number, since it uses less digits than its factorization.

21857950 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 437171 (or 437166 counting only the distinct ones).

The product of its (nonzero) digits is 25200, while the sum is 37.

The square root of 21857950 is about 4675.2486564888. The cubic root of 21857950 is about 279.5995551237.

The spelling of 21857950 in words is "twenty-one million, eight hundred fifty-seven thousand, nine hundred fifty".