20281604 has 24 divisors (see below), whose sum is σ = 41254080. Its totient is φ = 8544096.

The previous prime is 20281603. The next prime is 20281609. The reversal of 20281604 is 40618202.

It is a super-2 number, since 2×20281604² = 822686921625632, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20281604.

It is not an unprimeable number, because it can be changed into a prime (20281603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4487 + ... + 7790.

It is an arithmetic number, because the mean of its divisors is an integer number (1718920).

Almost surely, 2^20281604 is an apocalyptic number.

It is an amenable number.

20281604 is an abundant number, since it is smaller than the sum of its proper divisors (20972476).

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

20281604 is a wasteful number, since it uses less digits than its factorization.

20281604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12347 (or 12345 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 23.

The square root of 20281604 is about 4503.5101865101. The cubic root of 20281604 is about 272.7098134412.

Adding to 20281604 its reverse (40618202), we get a palindrome (60899806).

The spelling of 20281604 in words is "twenty million, two hundred eighty-one thousand, six hundred four".