21248497 has 4 divisors (see below), whose sum is σ = 21415936. Its totient is φ = 21081060.

The previous prime is 21248477. The next prime is 21248501. The reversal of 21248497 is 79484212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21248497 - 2⁷ = 21248369 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21248417) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 83529 + ... + 83782.

It is an arithmetic number, because the mean of its divisors is an integer number (5353984).

Almost surely, 2^21248497 is an apocalyptic number.

It is an amenable number.

21248497 is a deficient number, since it is larger than the sum of its proper divisors (167439).

21248497 is a wasteful number, since it uses less digits than its factorization.

21248497 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167438.

The product of its digits is 32256, while the sum is 37.

The square root of 21248497 is about 4609.6092025247. The cubic root of 21248497 is about 276.9763824043.

The spelling of 21248497 in words is "twenty-one million, two hundred forty-eight thousand, four hundred ninety-seven".