21456146 has 4 divisors (see below), whose sum is σ = 32184222. Its totient is φ = 10728072.

The previous prime is 21456139. The next prime is 21456151. The reversal of 21456146 is 64165412.

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., 16443025 + 5013121 = 4055^2 + 2239^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5364035 + ... + 5364038.

Almost surely, 2^21456146 is an apocalyptic number.

21456146 is a deficient number, since it is larger than the sum of its proper divisors (10728076).

21456146 is a wasteful number, since it uses less digits than its factorization.

21456146 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10728075.

The product of its digits is 5760, while the sum is 29.

The square root of 21456146 is about 4632.0779354411. The cubic root of 21456146 is about 277.8757013806.

The spelling of 21456146 in words is "twenty-one million, four hundred fifty-six thousand, one hundred forty-six".