21193447 has 8 divisors (see below), whose sum is σ = 23222160. Its totient is φ = 19181760.

The previous prime is 21193427. The next prime is 21193463. The reversal of 21193447 is 74439112.

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 21193447 - 2¹⁵ = 21160679 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 (21193427) 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, 1572 + ... + 6697.

It is an arithmetic number, because the mean of its divisors is an integer number (2902770).

Almost surely, 2^21193447 is an apocalyptic number.

21193447 is a deficient number, since it is larger than the sum of its proper divisors (2028713).

21193447 is a wasteful number, since it uses less digits than its factorization.

21193447 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8513.

The product of its digits is 6048, while the sum is 31.

The square root of 21193447 is about 4603.6341079630. The cubic root of 21193447 is about 276.7369813700.

The spelling of 21193447 in words is "twenty-one million, one hundred ninety-three thousand, four hundred forty-seven".