21197236 has 12 divisors (see below), whose sum is σ = 39047680. Its totient is φ = 10040760.

The previous prime is 21197221. The next prime is 21197251. The reversal of 21197236 is 63279112.

It is an interprime number because it is at equal distance from previous prime (21197221) and next prime (21197251).

It is a junction number, because it is equal to n+sod(n) for n = 21197198 and 21197207.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 139380 + ... + 139531.

Almost surely, 2^21197236 is an apocalyptic number.

It is an amenable number.

21197236 is a deficient number, since it is larger than the sum of its proper divisors (17850444).

21197236 is a wasteful number, since it uses less digits than its factorization.

21197236 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 278934 (or 278932 counting only the distinct ones).

The product of its digits is 4536, while the sum is 31.

The square root of 21197236 is about 4604.0456122849. The cubic root of 21197236 is about 276.7534722212.

The spelling of 21197236 in words is "twenty-one million, one hundred ninety-seven thousand, two hundred thirty-six".