21703197 has 4 divisors (see below), whose sum is σ = 28937600. Its totient is φ = 14468796.

The previous prime is 21703181. The next prime is 21703211. The reversal of 21703197 is 79130712.

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 not a de Polignac number, because 21703197 - 2⁴ = 21703181 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21703147) 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, 3617197 + ... + 3617202.

It is an arithmetic number, because the mean of its divisors is an integer number (7234400).

Almost surely, 2^21703197 is an apocalyptic number.

It is an amenable number.

21703197 is a deficient number, since it is larger than the sum of its proper divisors (7234403).

21703197 is an equidigital number, since it uses as much as digits as its factorization.

21703197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7234402.

The product of its (nonzero) digits is 2646, while the sum is 30.

The square root of 21703197 is about 4658.6690159315. The cubic root of 21703197 is about 278.9381422710.

The spelling of 21703197 in words is "twenty-one million, seven hundred three thousand, one hundred ninety-seven".