21066146 has 4 divisors (see below), whose sum is σ = 31599222. Its totient is φ = 10533072.

The previous prime is 21066113. The next prime is 21066181. The reversal of 21066146 is 64166012.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 21058921 + 7225 = 4589^2 + 85^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5266535 + ... + 5266538.

Almost surely, 2^21066146 is an apocalyptic number.

21066146 is a deficient number, since it is larger than the sum of its proper divisors (10533076).

21066146 is a wasteful number, since it uses less digits than its factorization.

21066146 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10533075.

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 21066146 is about 4589.7871410339. The cubic root of 21066146 is about 276.1817835561.

It can be divided in two parts, 21066 and 146, that added together give a palindrome (21212).

The spelling of 21066146 in words is "twenty-one million, sixty-six thousand, one hundred forty-six".