21054169 has 2 divisors, whose sum is σ = 21054170. Its totient is φ = 21054168.

The previous prime is 21054119. The next prime is 21054179. The reversal of 21054169 is 96145012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20142144 + 912025 = 4488^2 + 955^2 .

It is a cyclic number.

It is not a de Polignac number, because 21054169 - 2⁹ = 21053657 is a prime.

It is a super-2 number, since 2×21054169² = 886556064561122, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is equal to p_1333189 and since 21054169 and 1333189 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (21054119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10527084 + 10527085.

It is an arithmetic number, because the mean of its divisors is an integer number (10527085).

Almost surely, 2^21054169 is an apocalyptic number.

It is an amenable number.

21054169 is a deficient number, since it is larger than the sum of its proper divisors (1).

21054169 is an equidigital number, since it uses as much as digits as its factorization.

21054169 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 21054169 is about 4588.4822109277. The cubic root of 21054169 is about 276.1294332702.

The spelling of 21054169 in words is "twenty-one million, fifty-four thousand, one hundred sixty-nine".