21054771 has 12 divisors (see below), whose sum is σ = 31154760. Its totient is φ = 13693920.

The previous prime is 21054757. The next prime is 21054773. The reversal of 21054771 is 17745012.

It is not a de Polignac number, because 21054771 - 2⁷ = 21054643 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21054773) 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, 28161 + ... + 28898.

It is an arithmetic number, because the mean of its divisors is an integer number (2596230).

Almost surely, 2^21054771 is an apocalyptic number.

21054771 is a deficient number, since it is larger than the sum of its proper divisors (10099989).

21054771 is a wasteful number, since it uses less digits than its factorization.

21054771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57106 (or 57103 counting only the distinct ones).

The product of its (nonzero) digits is 1960, while the sum is 27.

The square root of 21054771 is about 4588.5478094927. The cubic root of 21054771 is about 276.1320650266.

Adding to 21054771 its reverse (17745012), we get a palindrome (38799783).

The spelling of 21054771 in words is "twenty-one million, fifty-four thousand, seven hundred seventy-one".