61221560 has 16 divisors (see below), whose sum is σ = 137748600. Its totient is φ = 24488608.

The previous prime is 61221529. The next prime is 61221583. The reversal of 61221560 is 6512216.

61221560 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 765230 + ... + 765309.

Almost surely, 2^61221560 is an apocalyptic number.

It is an amenable number.

61221560 is an abundant number, since it is smaller than the sum of its proper divisors (76527040).

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

61221560 is a wasteful number, since it uses less digits than its factorization.

61221560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1530550 (or 1530546 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 61221560 is about 7824.4207453332. The cubic root of 61221560 is about 394.1257382533.

Adding to 61221560 its reverse (6512216), we get a palindrome (67733776).

The spelling of 61221560 in words is "sixty-one million, two hundred twenty-one thousand, five hundred sixty".