21011197 has 8 divisors (see below), whose sum is σ = 21264192. Its totient is φ = 20760000.

The previous prime is 21011191. The next prime is 21011231. The reversal of 21011197 is 79111012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21011197 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 (21011191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 52197 + ... + 52597.

It is an arithmetic number, because the mean of its divisors is an integer number (2658024).

Almost surely, 2^21011197 is an apocalyptic number.

It is an amenable number.

21011197 is a deficient number, since it is larger than the sum of its proper divisors (252995).

21011197 is a wasteful number, since it uses less digits than its factorization.

21011197 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 899.

The product of its (nonzero) digits is 126, while the sum is 22.

The square root of 21011197 is about 4583.7972250090. The cubic root of 21011197 is about 275.9414433290.

The spelling of 21011197 in words is "twenty-one million, eleven thousand, one hundred ninety-seven".