61221760 has 96 divisors (see below), whose sum is σ = 155943720. Its totient is φ = 22978560.

The previous prime is 61221749. The next prime is 61221793. The reversal of 61221760 is 6712216.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 184795 + ... + 185125.

Almost surely, 2^61221760 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 61221760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (77971860).

61221760 is an abundant number, since it is smaller than the sum of its proper divisors (94721960).

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

61221760 is a wasteful number, since it uses less digits than its factorization.

61221760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 384 (or 355 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 25.

The square root of 61221760 is about 7824.4335258215. The cubic root of 61221760 is about 394.1261674325.

Adding to 61221760 its reverse (6712216), we get a palindrome (67933976).

The spelling of 61221760 in words is "sixty-one million, two hundred twenty-one thousand, seven hundred sixty".