1221967745628 has 48 divisors (see below), whose sum is σ = 3259483368960. Its totient is φ = 349036922304.

The previous prime is 1221967745569. The next prime is 1221967745629. The reversal of 1221967745628 is 8265477691221.

It is a super-2 number, since 2×1221967745628² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221967745629) 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 15 ways as a sum of consecutive naturals, for example, 1709688 + ... + 2316671.

It is an arithmetic number, because the mean of its divisors is an integer number (67905903520).

Almost surely, 2^{1221967745628} is an apocalyptic number.

It is an amenable number.

1221967745628 is an abundant number, since it is smaller than the sum of its proper divisors (2037515623332).

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

1221967745628 is a wasteful number, since it uses less digits than its factorization.

1221967745628 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4029986 (or 4029984 counting only the distinct ones).

The product of its digits is 20321280, while the sum is 60.

The spelling of 1221967745628 in words is "one trillion, two hundred twenty-one billion, nine hundred sixty-seven million, seven hundred forty-five thousand, six hundred twenty-eight".