1290879996561 has 15 divisors (see below), whose sum is σ = 1928366875083. Its totient is φ = 860579847360.

The previous prime is 1290879996551. The next prime is 1290879996583. The reversal of 1290879996561 is 1656999780921.

The square root of 1290879996561 is 1136169.

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., 70208570961 + 1220671425600 = 264969^2 + 1104840^2 .

It is not a de Polignac number, because 1290879996561 - 2¹¹ = 1290879994513 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1290879996561.

It is not an unprimeable number, because it can be changed into a prime (1290879996551) by changing a digit.

It is a polite number, since it can be written in 14 ways as a sum of consecutive naturals, for example, 10162401 + ... + 10288641.

Almost surely, 2^{1290879996561} is an apocalyptic number.

1290879996561 is the 1136169-th square number.

1290879996561 is the 568085-th centered octagonal number.

It is an amenable number.

1290879996561 is a deficient number, since it is larger than the sum of its proper divisors (637486878522).

1290879996561 is an frugal number, since it uses more digits than its factorization.

1290879996561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 252494 (or 126244 counting only the distinct ones).

The product of its (nonzero) digits is 132269760, while the sum is 72.

The spelling of 1290879996561 in words is "one trillion, two hundred ninety billion, eight hundred seventy-nine million, nine hundred ninety-six thousand, five hundred sixty-one".