21789950 has 48 divisors (see below), whose sum is σ = 49892640. Its totient is φ = 6894720.

The previous prime is 21789919. The next prime is 21789967. The reversal of 21789950 is 5998712.

It is a junction number, because it is equal to n+sod(n) for n = 21789898 and 21789907.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2156 + ... + 6944.

It is an arithmetic number, because the mean of its divisors is an integer number (1039430).

Almost surely, 2^21789950 is an apocalyptic number.

21789950 is an abundant number, since it is smaller than the sum of its proper divisors (28102690).

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

21789950 is a wasteful number, since it uses less digits than its factorization.

21789950 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4821 (or 4816 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 41.

The square root of 21789950 is about 4667.9706511502. The cubic root of 21789950 is about 279.3093095439.

The spelling of 21789950 in words is "twenty-one million, seven hundred eighty-nine thousand, nine hundred fifty".