1221725560 has 32 divisors (see below), whose sum is σ = 2998782000. Its totient is φ = 444263680.

The previous prime is 1221725513. The next prime is 1221725563. The reversal of 1221725560 is 655271221.

It is a super-2 number, since 2×1221725560² = 2985226687914627200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221725563) 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 7 ways as a sum of consecutive naturals, for example, 1387885 + ... + 1388764.

Almost surely, 2^1221725560 is an apocalyptic number.

1221725560 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221725560 is an abundant number, since it is smaller than the sum of its proper divisors (1777056440).

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

1221725560 is a wasteful number, since it uses less digits than its factorization.

1221725560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2776671 (or 2776667 counting only the distinct ones).

The product of its (nonzero) digits is 8400, while the sum is 31.

The square root of 1221725560 is about 34953.1909845153. The cubic root of 1221725560 is about 1069.0332666384.

Adding to 1221725560 its reverse (655271221), we get a palindrome (1876996781).

The spelling of 1221725560 in words is "one billion, two hundred twenty-one million, seven hundred twenty-five thousand, five hundred sixty".