1275128774656 has 153 divisors (see below), whose sum is σ = 2810162108929. Its totient is φ = 578158592000.

The previous prime is 1275128774641. The next prime is 1275128774657. The reversal of 1275128774656 is 6564778215721.

The square root of 1275128774656 is 1129216.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 1262441005056 + 12687769600 = 1123584^2 + 112640^2 .

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1275128774594 and 1275128774603.

It is not an unprimeable number, because it can be changed into a prime (1275128774657) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 3179872056 + ... + 3179872456.

Almost surely, 2^{1275128774656} is an apocalyptic number.

1275128774656 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

1275128774656 is the 1129216-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1275128774656

1275128774656 is an abundant number, since it is smaller than the sum of its proper divisors (1535033334273).

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

1275128774656 is an frugal number, since it uses more digits than its factorization.

1275128774656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 856 (or 414 counting only the distinct ones).

The product of its digits is 39513600, while the sum is 61.

The spelling of 1275128774656 in words is "one trillion, two hundred seventy-five billion, one hundred twenty-eight million, seven hundred seventy-four thousand, six hundred fifty-six".