21497324 has 6 divisors (see below), whose sum is σ = 37620324. Its totient is φ = 10748660.

The previous prime is 21497321. The next prime is 21497339. The reversal of 21497324 is 42379412.

It is not an unprimeable number, because it can be changed into a prime (21497321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2687162 + ... + 2687169.

It is an arithmetic number, because the mean of its divisors is an integer number (6270054).

Almost surely, 2^21497324 is an apocalyptic number.

It is an amenable number.

21497324 is a deficient number, since it is larger than the sum of its proper divisors (16123000).

21497324 is a wasteful number, since it uses less digits than its factorization.

21497324 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5374335 (or 5374333 counting only the distinct ones).

The product of its digits is 12096, while the sum is 32.

The square root of 21497324 is about 4636.5206782673. The cubic root of 21497324 is about 278.0533513878.

The spelling of 21497324 in words is "twenty-one million, four hundred ninety-seven thousand, three hundred twenty-four".