20261604 has 96 divisors (see below), whose sum is σ = 54835200. Its totient is φ = 5765760.

The previous prime is 20261599. The next prime is 20261617. The reversal of 20261604 is 40616202.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 256437 + ... + 256515.

It is an arithmetic number, because the mean of its divisors is an integer number (571200).

Almost surely, 2^20261604 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 20261604, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27417600).

20261604 is an abundant number, since it is smaller than the sum of its proper divisors (34573596).

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

20261604 is a wasteful number, since it uses less digits than its factorization.

20261604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193 (or 191 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 20261604 is about 4501.2891486773. The cubic root of 20261604 is about 272.6201428532.

Adding to 20261604 its reverse (40616202), we get a palindrome (60877806).

The spelling of 20261604 in words is "twenty million, two hundred sixty-one thousand, six hundred four".