20247818 has 4 divisors (see below), whose sum is σ = 30371730. Its totient is φ = 10123908.

The previous prime is 20247817. The next prime is 20247827. The reversal of 20247818 is 81874202.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 81874202 = 2 ⋅40937101.

It can be written as a sum of positive squares in only one way, i.e., 19829209 + 418609 = 4453^2 + 647^2 .

It is a super-2 number, since 2×20247818² = 819948267522248, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20247811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5061953 + ... + 5061956.

Almost surely, 2^20247818 is an apocalyptic number.

20247818 is a deficient number, since it is larger than the sum of its proper divisors (10123912).

20247818 is a wasteful number, since it uses less digits than its factorization.

20247818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10123911.

The product of its (nonzero) digits is 7168, while the sum is 32.

The square root of 20247818 is about 4499.7575490242. The cubic root of 20247818 is about 272.5582985556.

The spelling of 20247818 in words is "twenty million, two hundred forty-seven thousand, eight hundred eighteen".