61604220 has 48 divisors (see below), whose sum is σ = 173577600. Its totient is φ = 16324416.

The previous prime is 61604219. The next prime is 61604227. The reversal of 61604220 is 2240616.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61604227) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6631 + ... + 12929.

It is an arithmetic number, because the mean of its divisors is an integer number (3616200).

Almost surely, 2^61604220 is an apocalyptic number.

61604220 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61604220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (86788800).

61604220 is an abundant number, since it is smaller than the sum of its proper divisors (111973380).

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

61604220 is a wasteful number, since it uses less digits than its factorization.

61604220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6474 (or 6472 counting only the distinct ones).

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

The square root of 61604220 is about 7848.8355824288. The cubic root of 61604220 is about 394.9451828005.

Adding to 61604220 its reverse (2240616), we get a palindrome (63844836).

The spelling of 61604220 in words is "sixty-one million, six hundred four thousand, two hundred twenty".