1221755277552 has 40 divisors (see below), whose sum is σ = 3169407025920. Its totient is φ = 405547773120.

The previous prime is 1221755277539. The next prime is 1221755277553. The reversal of 1221755277552 is 2557725571221.

It is a super-2 number, since 2×1221755277552² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1221755277495 and 1221755277504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221755277553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 53237974 + ... + 53260917.

It is an arithmetic number, because the mean of its divisors is an integer number (79235175648).

Almost surely, 2^{1221755277552} is an apocalyptic number.

1221755277552 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1221755277552 is an abundant number, since it is smaller than the sum of its proper divisors (1947651748368).

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

1221755277552 is a wasteful number, since it uses less digits than its factorization.

1221755277552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106499141 (or 106499135 counting only the distinct ones).

The product of its digits is 3430000, while the sum is 51.

The spelling of 1221755277552 in words is "one trillion, two hundred twenty-one billion, seven hundred fifty-five million, two hundred seventy-seven thousand, five hundred fifty-two".