21056146 has 8 divisors (see below), whose sum is σ = 32673420. Its totient is φ = 10165008.

The previous prime is 21056143. The next prime is 21056153. The reversal of 21056146 is 64165012.

It can be written as a sum of positive squares in 2 ways, for example, as 19900521 + 1155625 = 4461^2 + 1075^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×21056146² = 886722568746632, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21056146.

It is not an unprimeable number, because it can be changed into a prime (21056143) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 181461 + ... + 181576.

Almost surely, 2^21056146 is an apocalyptic number.

21056146 is a deficient number, since it is larger than the sum of its proper divisors (11617274).

21056146 is a wasteful number, since it uses less digits than its factorization.

21056146 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 363068.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 21056146 is about 4588.6976365849. The cubic root of 21056146 is about 276.1380759101.

The spelling of 21056146 in words is "twenty-one million, fifty-six thousand, one hundred forty-six".