21617080 has 32 divisors (see below), whose sum is σ = 48839040. Its totient is φ = 8611200.

The previous prime is 21617053. The next prime is 21617111. The reversal of 21617080 is 8071612.

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 7 ways as a sum of consecutive naturals, for example, 10105 + ... + 12055.

It is an arithmetic number, because the mean of its divisors is an integer number (1526220).

Almost surely, 2^21617080 is an apocalyptic number.

21617080 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21617080 is an abundant number, since it is smaller than the sum of its proper divisors (27221960).

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

21617080 is a wasteful number, since it uses less digits than its factorization.

21617080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2239 (or 2235 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 25.

The square root of 21617080 is about 4649.4171677749. The cubic root of 21617080 is about 278.5687165448.

Adding to 21617080 its reverse (8071612), we get a palindrome (29688692).

The spelling of 21617080 in words is "twenty-one million, six hundred seventeen thousand, eighty".