20818642 has 64 divisors (see below), whose sum is σ = 39070080. Its totient is φ = 8211456.

The previous prime is 20818621. The next prime is 20818643. The reversal of 20818642 is 24681802.

It is not an unprimeable number, because it can be changed into a prime (20818643) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 310693 + ... + 310759.

It is an arithmetic number, because the mean of its divisors is an integer number (610470).

Almost surely, 2^20818642 is an apocalyptic number.

20818642 is a deficient number, since it is larger than the sum of its proper divisors (18251438).

20818642 is a wasteful number, since it uses less digits than its factorization.

20818642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155.

The product of its (nonzero) digits is 6144, while the sum is 31.

The square root of 20818642 is about 4562.7450071202. The cubic root of 20818642 is about 275.0959092464.

The spelling of 20818642 in words is "twenty million, eight hundred eighteen thousand, six hundred forty-two".