21054879 has 18 divisors (see below), whose sum is σ = 30905160. Its totient is φ = 13812768.

The previous prime is 21054871. The next prime is 21054881. The reversal of 21054879 is 97845012.

It is not a de Polignac number, because 21054879 - 2³ = 21054871 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21054871) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 47742 + ... + 48180.

Almost surely, 2^21054879 is an apocalyptic number.

21054879 is a deficient number, since it is larger than the sum of its proper divisors (9850281).

21054879 is an equidigital number, since it uses as much as digits as its factorization.

21054879 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 591 (or 515 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 21054879 is about 4588.5595779068. The cubic root of 21054879 is about 276.1325371637.

The spelling of 21054879 in words is "twenty-one million, fifty-four thousand, eight hundred seventy-nine".