21194791 has 8 divisors (see below), whose sum is σ = 21873600. Its totient is φ = 20525568.

The previous prime is 21194783. The next prime is 21194819. The reversal of 21194791 is 19749112.

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

It is a cyclic number.

It is not a de Polignac number, because 21194791 - 2³ = 21194783 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 (21192791) 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 7 ways as a sum of consecutive naturals, for example, 2235 + ... + 6883.

It is an arithmetic number, because the mean of its divisors is an integer number (2734200).

Almost surely, 2^21194791 is an apocalyptic number.

21194791 is a deficient number, since it is larger than the sum of its proper divisors (678809).

21194791 is an equidigital number, since it uses as much as digits as its factorization.

21194791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4793.

The product of its digits is 4536, while the sum is 34.

The square root of 21194791 is about 4603.7800772843. The cubic root of 21194791 is about 276.7428310813.

The spelling of 21194791 in words is "twenty-one million, one hundred ninety-four thousand, seven hundred ninety-one".