1351123501561 has 4 divisors (see below), whose sum is σ = 1430601354612. Its totient is φ = 1271645648512.

The previous prime is 1351123501549. The next prime is 1351123501639. The reversal of 1351123501561 is 1651053211531.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1028449515625 + 322673985936 = 1014125^2 + 568044^2 .

It is a cyclic number.

It is not a de Polignac number, because 1351123501561 - 2⁷ = 1351123501433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1351123501061) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39738926500 + ... + 39738926533.

It is an arithmetic number, because the mean of its divisors is an integer number (357650338653).

Almost surely, 2^{1351123501561} is an apocalyptic number.

It is an amenable number.

1351123501561 is a deficient number, since it is larger than the sum of its proper divisors (79477853051).

1351123501561 is an equidigital number, since it uses as much as digits as its factorization.

1351123501561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79477853050.

The product of its (nonzero) digits is 13500, while the sum is 34.

The spelling of 1351123501561 in words is "one trillion, three hundred fifty-one billion, one hundred twenty-three million, five hundred one thousand, five hundred sixty-one".