21203047 has 8 divisors (see below), whose sum is σ = 21565440. Its totient is φ = 20843160.

The previous prime is 21203041. The next prime is 21203071. The reversal of 21203047 is 74030212.

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 21203047 - 2⁷ = 21202919 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 (21203041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24138 + ... + 25000.

It is an arithmetic number, because the mean of its divisors is an integer number (2695680).

Almost surely, 2^21203047 is an apocalyptic number.

21203047 is a deficient number, since it is larger than the sum of its proper divisors (362393).

21203047 is an equidigital number, since it uses as much as digits as its factorization.

21203047 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1253.

The product of its (nonzero) digits is 336, while the sum is 19.

The square root of 21203047 is about 4604.6766444562. The cubic root of 21203047 is about 276.7787595981.

Adding to 21203047 its reverse (74030212), we get a palindrome (95233259).

The spelling of 21203047 in words is "twenty-one million, two hundred three thousand, forty-seven".