1220728566640 has 320 divisors, whose sum is σ = 3164547170304. Its totient is φ = 437876736000.

The previous prime is 1220728566637. The next prime is 1220728566643. The reversal of 1220728566640 is 466658270221.

It is an interprime number because it is at equal distance from previous prime (1220728566637) and next prime (1220728566643).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220728566643) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3925172085 + ... + 3925172395.

Almost surely, 2^{1220728566640} is an apocalyptic number.

1220728566640 is a gapful number since it is divisible by the number (10) 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 1220728566640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1582273585152).

1220728566640 is an abundant number, since it is smaller than the sum of its proper divisors (1943818603664).

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

1220728566640 is a wasteful number, since it uses less digits than its factorization.

1220728566640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 741 (or 713 counting only the distinct ones).

The product of its (nonzero) digits is 1935360, while the sum is 49.

The spelling of 1220728566640 in words is "one trillion, two hundred twenty billion, seven hundred twenty-eight million, five hundred sixty-six thousand, six hundred forty".