20618004 has 48 divisors (see below), whose sum is σ = 53000640. Its totient is φ = 6186240.

The previous prime is 20617999. The next prime is 20618011. The reversal of 20618004 is 40081602.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13672 + ... + 15104.

It is an arithmetic number, because the mean of its divisors is an integer number (1104180).

Almost surely, 2^20618004 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20618004, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26500320).

20618004 is an abundant number, since it is smaller than the sum of its proper divisors (32382636).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20618004 is a wasteful number, since it uses less digits than its factorization.

20618004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1560 (or 1558 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 20618004 is about 4540.7052315692. The cubic root of 20618004 is about 274.2093166754.

Adding to 20618004 its reverse (40081602), we get a palindrome (60699606).

The spelling of 20618004 in words is "twenty million, six hundred eighteen thousand, four".