20868578 has 4 divisors (see below), whose sum is σ = 31302870. Its totient is φ = 10434288.

The previous prime is 20868577. The next prime is 20868581. The reversal of 20868578 is 87586802.

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., 18983449 + 1885129 = 4357^2 + 1373^2 .

It is not an unprimeable number, because it can be changed into a prime (20868577) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5217143 + ... + 5217146.

Almost surely, 2^20868578 is an apocalyptic number.

20868578 is a deficient number, since it is larger than the sum of its proper divisors (10434292).

20868578 is a wasteful number, since it uses less digits than its factorization.

20868578 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10434291.

The product of its (nonzero) digits is 215040, while the sum is 44.

The square root of 20868578 is about 4568.2138741526. The cubic root of 20868578 is about 275.3156837560.

It can be divided in two parts, 208 and 68578, that added together give a palindrome (68786).

The spelling of 20868578 in words is "twenty million, eight hundred sixty-eight thousand, five hundred seventy-eight".