1015121320561 has 2 divisors, whose sum is σ = 1015121320562. Its totient is φ = 1015121320560.

The previous prime is 1015121320513. The next prime is 1015121320573. The reversal of 1015121320561 is 1650231215101.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 916049981025 + 99071339536 = 957105^2 + 314756^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1015121320561 is a prime.

It is not a weakly prime, because it can be changed into another prime (1015121321561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 507560660280 + 507560660281.

It is an arithmetic number, because the mean of its divisors is an integer number (507560660281).

Almost surely, 2^{1015121320561} is an apocalyptic number.

It is an amenable number.

1015121320561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1015121320561 is an equidigital number, since it uses as much as digits as its factorization.

1015121320561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1800, while the sum is 28.

Adding to 1015121320561 its reverse (1650231215101), we get a palindrome (2665352535662).

The spelling of 1015121320561 in words is "one trillion, fifteen billion, one hundred twenty-one million, three hundred twenty thousand, five hundred sixty-one".