20864618 has 4 divisors (see below), whose sum is σ = 31296930. Its totient is φ = 10432308.

The previous prime is 20864617. The next prime is 20864647. The reversal of 20864618 is 81646802.

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., 11580409 + 9284209 = 3403^2 + 3047^2 .

It is not an unprimeable number, because it can be changed into a prime (20864617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5216153 + ... + 5216156.

Almost surely, 2^20864618 is an apocalyptic number.

20864618 is a deficient number, since it is larger than the sum of its proper divisors (10432312).

20864618 is a wasteful number, since it uses less digits than its factorization.

20864618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10432311.

The product of its (nonzero) digits is 18432, while the sum is 35.

The square root of 20864618 is about 4567.7804237945. The cubic root of 20864618 is about 275.2982681136.

The spelling of 20864618 in words is "twenty million, eight hundred sixty-four thousand, six hundred eighteen".