21190347 has 18 divisors (see below), whose sum is σ = 32518668. Its totient is φ = 13294272.

The previous prime is 21190343. The next prime is 21190349. The reversal of 21190347 is 74309112.

It is not a de Polignac number, because 21190347 - 2² = 21190343 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21190347.

It is not an unprimeable number, because it can be changed into a prime (21190343) 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 17 ways as a sum of consecutive naturals, for example, 1473 + ... + 6674.

Almost surely, 2^21190347 is an apocalyptic number.

21190347 is a deficient number, since it is larger than the sum of its proper divisors (11328321).

21190347 is a wasteful number, since it uses less digits than its factorization.

21190347 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8187 (or 8167 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 27.

The square root of 21190347 is about 4603.2974051217. The cubic root of 21190347 is about 276.7234877891.

Adding to 21190347 its reverse (74309112), we get a palindrome (95499459).

The spelling of 21190347 in words is "twenty-one million, one hundred ninety thousand, three hundred forty-seven".