21292197 has 4 divisors (see below), whose sum is σ = 28389600. Its totient is φ = 14194796.

The previous prime is 21292189. The next prime is 21292231. The reversal of 21292197 is 79129212.

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 21292197 - 2³ = 21292189 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21292147) 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 3 ways as a sum of consecutive naturals, for example, 3548697 + ... + 3548702.

It is an arithmetic number, because the mean of its divisors is an integer number (7097400).

Almost surely, 2^21292197 is an apocalyptic number.

It is an amenable number.

21292197 is a deficient number, since it is larger than the sum of its proper divisors (7097403).

21292197 is an equidigital number, since it uses as much as digits as its factorization.

21292197 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7097402.

The product of its digits is 4536, while the sum is 33.

The square root of 21292197 is about 4614.3468660256. The cubic root of 21292197 is about 277.1661304087.

The spelling of 21292197 in words is "twenty-one million, two hundred ninety-two thousand, one hundred ninety-seven".