21001193 has 4 divisors (see below), whose sum is σ = 21010560. Its totient is φ = 20991828.

The previous prime is 21001187. The next prime is 21001247. The reversal of 21001193 is 39110012.

It is a happy number.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21001193 - 2⁴ = 21001177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21001153) 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, 896 + ... + 6542.

It is an arithmetic number, because the mean of its divisors is an integer number (5252640).

Almost surely, 2^21001193 is an apocalyptic number.

It is an amenable number.

21001193 is a deficient number, since it is larger than the sum of its proper divisors (9367).

21001193 is an equidigital number, since it uses as much as digits as its factorization.

21001193 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9366.

The product of its (nonzero) digits is 54, while the sum is 17.

The square root of 21001193 is about 4582.7058600787. The cubic root of 21001193 is about 275.8976419781.

The spelling of 21001193 in words is "twenty-one million, one thousand, one hundred ninety-three".