21452986 has 4 divisors (see below), whose sum is σ = 32179482. Its totient is φ = 10726492.

The previous prime is 21452947. The next prime is 21452989. The reversal of 21452986 is 68925412.

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., 12638025 + 8814961 = 3555^2 + 2969^2 .

It is not an unprimeable number, because it can be changed into a prime (21452989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5363245 + ... + 5363248.

Almost surely, 2^21452986 is an apocalyptic number.

21452986 is a deficient number, since it is larger than the sum of its proper divisors (10726496).

21452986 is a wasteful number, since it uses less digits than its factorization.

21452986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10726495.

The product of its digits is 34560, while the sum is 37.

The square root of 21452986 is about 4631.7368232662. The cubic root of 21452986 is about 277.8620591306.

The spelling of 21452986 in words is "twenty-one million, four hundred fifty-two thousand, nine hundred eighty-six".