21361047 has 16 divisors (see below), whose sum is σ = 29053440. Its totient is φ = 13957632.

The previous prime is 21361031. The next prime is 21361051. The reversal of 21361047 is 74016312.

It is not a de Polignac number, because 21361047 - 2⁴ = 21361031 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21361097) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 45508 + ... + 45974.

It is an arithmetic number, because the mean of its divisors is an integer number (1815840).

Almost surely, 2^21361047 is an apocalyptic number.

21361047 is a deficient number, since it is larger than the sum of its proper divisors (7692393).

21361047 is a wasteful number, since it uses less digits than its factorization.

21361047 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 742.

The product of its (nonzero) digits is 1008, while the sum is 24.

The square root of 21361047 is about 4621.8012722314. The cubic root of 21361047 is about 277.4645551677.

Adding to 21361047 its reverse (74016312), we get a palindrome (95377359).

The spelling of 21361047 in words is "twenty-one million, three hundred sixty-one thousand, forty-seven".