21050847 has 12 divisors (see below), whose sum is σ = 31533320. Its totient is φ = 14033736.

The previous prime is 21050833. The next prime is 21050857. The reversal of 21050847 is 74805012.

It is not a de Polignac number, because 21050847 - 2⁸ = 21050591 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21050847.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21050807) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 43072 + ... + 43557.

Almost surely, 2^21050847 is an apocalyptic number.

21050847 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

21050847 is a deficient number, since it is larger than the sum of its proper divisors (10482473).

21050847 is an frugal number, since it uses more digits than its factorization.

21050847 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86644 (or 86632 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 21050847 is about 4588.1202033077. The cubic root of 21050847 is about 276.1149096189.

Adding to 21050847 its reverse (74805012), we get a palindrome (95855859).

The spelling of 21050847 in words is "twenty-one million, fifty thousand, eight hundred forty-seven".