21232047 has 4 divisors (see below), whose sum is σ = 28309400. Its totient is φ = 14154696.

The previous prime is 21232033. The next prime is 21232049. The reversal of 21232047 is 74023212.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21232047 - 2¹⁶ = 21166511 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 (21232049) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3538672 + ... + 3538677.

It is an arithmetic number, because the mean of its divisors is an integer number (7077350).

Almost surely, 2^21232047 is an apocalyptic number.

21232047 is a deficient number, since it is larger than the sum of its proper divisors (7077353).

21232047 is an equidigital number, since it uses as much as digits as its factorization.

21232047 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7077352.

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

The square root of 21232047 is about 4607.8245409304. The cubic root of 21232047 is about 276.9048881275.

Adding to 21232047 its reverse (74023212), we get a palindrome (95255259).

The spelling of 21232047 in words is "twenty-one million, two hundred thirty-two thousand, forty-seven".