21294591 has 8 divisors (see below), whose sum is σ = 30063024. Its totient is φ = 13361280.

The previous prime is 21294587. The next prime is 21294617. The reversal of 21294591 is 19549212.

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

It is not a de Polignac number, because 21294591 - 2² = 21294587 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21294541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 208720 + ... + 208821.

It is an arithmetic number, because the mean of its divisors is an integer number (3757878).

Almost surely, 2^21294591 is an apocalyptic number.

21294591 is a deficient number, since it is larger than the sum of its proper divisors (8768433).

21294591 is a wasteful number, since it uses less digits than its factorization.

21294591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 417561.

The product of its digits is 6480, while the sum is 33.

The square root of 21294591 is about 4614.6062670611. The cubic root of 21294591 is about 277.1765177954.

The spelling of 21294591 in words is "twenty-one million, two hundred ninety-four thousand, five hundred ninety-one".