21417552 has 120 divisors (see below), whose sum is σ = 68448744. Its totient is φ = 6193152.

The previous prime is 21417547. The next prime is 21417553. The reversal of 21417552 is 25571412.

It can be written as a sum of positive squares in 4 ways, for example, as 1382976 + 20034576 = 1176^2 + 4476^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21417553) 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 in 23 ways as a sum of consecutive naturals, for example, 31488 + ... + 32160.

Almost surely, 2^21417552 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21417552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34224372).

21417552 is an abundant number, since it is smaller than the sum of its proper divisors (47031192).

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

21417552 is a wasteful number, since it uses less digits than its factorization.

21417552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 717 (or 708 counting only the distinct ones).

The product of its digits is 2800, while the sum is 27.

The square root of 21417552 is about 4627.9101114866. The cubic root of 21417552 is about 277.7089927936.

Adding to 21417552 its reverse (25571412), we get a palindrome (46988964).

It can be divided in two parts, 214 and 17552, that added together give a triangular number (17766 = T₁₈₈).

The spelling of 21417552 in words is "twenty-one million, four hundred seventeen thousand, five hundred fifty-two".