21985950 has 48 divisors (see below), whose sum is σ = 62317440. Its totient is φ = 5025120.

The previous prime is 21985949. The next prime is 21985961. The reversal of 21985950 is 5958912.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21985899 and 21985908.

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, 9420 + ... + 11519.

It is an arithmetic number, because the mean of its divisors is an integer number (1298280).

Almost surely, 2^21985950 is an apocalyptic number.

21985950 is an abundant number, since it is smaller than the sum of its proper divisors (40331490).

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

21985950 is a wasteful number, since it uses less digits than its factorization.

21985950 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20961 (or 20956 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 39.

The square root of 21985950 is about 4688.9177855876. The cubic root of 21985950 is about 280.1442708893.

The spelling of 21985950 in words is "twenty-one million, nine hundred eighty-five thousand, nine hundred fifty".