21617248 has 12 divisors (see below), whose sum is σ = 42559020. Its totient is φ = 10808608.

The previous prime is 21617243. The next prime is 21617249. The reversal of 21617248 is 84271612.

It is a super-2 number, since 2×21617248² = 934610822187008, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21617243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 337738 + ... + 337801.

It is an arithmetic number, because the mean of its divisors is an integer number (3546585).

Almost surely, 2^21617248 is an apocalyptic number.

It is an amenable number.

21617248 is a deficient number, since it is larger than the sum of its proper divisors (20941772).

21617248 is an equidigital number, since it uses as much as digits as its factorization.

21617248 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 675549 (or 675541 counting only the distinct ones).

The product of its digits is 5376, while the sum is 31.

The square root of 21617248 is about 4649.4352345204. The cubic root of 21617248 is about 278.5694381875.

It can be divided in two parts, 2161 and 7248, that added together give a square (9409 = 97²).

The spelling of 21617248 in words is "twenty-one million, six hundred seventeen thousand, two hundred forty-eight".