21064618 has 8 divisors (see below), whose sum is σ = 32451012. Its totient is φ = 10247616.

The previous prime is 21064607. The next prime is 21064621. The reversal of 21064618 is 81646012.

It can be written as a sum of positive squares in 2 ways, for example, as 20584369 + 480249 = 4537^2 + 693^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 142255 + ... + 142402.

Almost surely, 2^21064618 is an apocalyptic number.

21064618 is a deficient number, since it is larger than the sum of its proper divisors (11386394).

21064618 is a wasteful number, since it uses less digits than its factorization.

21064618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 284696.

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 21064618 is about 4589.6206814943. The cubic root of 21064618 is about 276.1751059232.

It can be divided in two parts, 2106 and 4618, that added together give a square (6724 = 82²).

The spelling of 21064618 in words is "twenty-one million, sixty-four thousand, six hundred eighteen".