61221360 has 80 divisors (see below), whose sum is σ = 193407264. Its totient is φ = 16014336.

The previous prime is 61221353. The next prime is 61221361. The reversal of 61221360 is 6312216.

61221360 = 310² + 311² + ... + 597².

It is a happy number.

61221360 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61221361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10314 + ... + 15126.

Almost surely, 2^61221360 is an apocalyptic number.

61221360 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 61221360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96703632).

61221360 is an abundant number, since it is smaller than the sum of its proper divisors (132185904).

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

61221360 is a wasteful number, since it uses less digits than its factorization.

61221360 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4882 (or 4876 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 61221360 is about 7824.4079648239. The cubic root of 61221360 is about 394.1253090731.

Adding to 61221360 its reverse (6312216), we get a palindrome (67533576).

The spelling of 61221360 in words is "sixty-one million, two hundred twenty-one thousand, three hundred sixty".