21224115 has 48 divisors (see below), whose sum is σ = 40940640. Its totient is φ = 10083840.

The previous prime is 21224087. The next prime is 21224123. The reversal of 21224115 is 51142212.

21224115 = 594² + 595² + ... + 648².

It is not a de Polignac number, because 21224115 - 2⁹ = 21223603 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 25831 + ... + 26639.

It is an arithmetic number, because the mean of its divisors is an integer number (852930).

Almost surely, 2^21224115 is an apocalyptic number.

21224115 is a deficient number, since it is larger than the sum of its proper divisors (19716525).

21224115 is a wasteful number, since it uses less digits than its factorization.

21224115 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 884 (or 881 counting only the distinct ones).

The product of its digits is 160, while the sum is 18.

The square root of 21224115 is about 4606.9637506714. The cubic root of 21224115 is about 276.8704012165.

Adding to 21224115 its reverse (51142212), we get a palindrome (72366327).

The spelling of 21224115 in words is "twenty-one million, two hundred twenty-four thousand, one hundred fifteen".