21617934 has 64 divisors (see below), whose sum is σ = 50803200. Its totient is φ = 6072192.

The previous prime is 21617927. The next prime is 21617969. The reversal of 21617934 is 43971612.

It is a junction number, because it is equal to n+sod(n) for n = 21617895 and 21617904.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 42727 + ... + 43229.

It is an arithmetic number, because the mean of its divisors is an integer number (793800).

Almost surely, 2^21617934 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21617934, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25401600).

21617934 is an abundant number, since it is smaller than the sum of its proper divisors (29185266).

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

21617934 is a wasteful number, since it uses less digits than its factorization.

21617934 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 569.

The product of its digits is 9072, while the sum is 33.

The square root of 21617934 is about 4649.5090063360. The cubic root of 21617934 is about 278.5723848563.

The spelling of 21617934 in words is "twenty-one million, six hundred seventeen thousand, nine hundred thirty-four".