21034047 has 16 divisors (see below), whose sum is σ = 28651392. Its totient is φ = 13722720.

The previous prime is 21034043. The next prime is 21034061. The reversal of 21034047 is 74043012.

It is not a de Polignac number, because 21034047 - 2² = 21034043 is a prime.

It is a super-2 number, since 2×21034047² = 884862266396418, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21034043) 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 15 ways as a sum of consecutive naturals, for example, 45397 + ... + 45857.

It is an arithmetic number, because the mean of its divisors is an integer number (1790712).

Almost surely, 2^21034047 is an apocalyptic number.

21034047 is a deficient number, since it is larger than the sum of its proper divisors (7617345).

21034047 is a wasteful number, since it uses less digits than its factorization.

21034047 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 758.

The product of its (nonzero) digits is 672, while the sum is 21.

The square root of 21034047 is about 4586.2890227285. The cubic root of 21034047 is about 276.0414372778.

Adding to 21034047 its reverse (74043012), we get a palindrome (95077059).

The spelling of 21034047 in words is "twenty-one million, thirty-four thousand, forty-seven".