1264202440561 has 4 divisors (see below), whose sum is σ = 1288055316852. Its totient is φ = 1240349564272.

The previous prime is 1264202440537. The next prime is 1264202440577. The reversal of 1264202440561 is 1650442024621.

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 1136449809936 + 127752630625 = 1066044^2 + 357425^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1264202440561 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1264202440561.

It is not an unprimeable number, because it can be changed into a prime (1264202440511) 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, 11926438066 + ... + 11926438171.

It is an arithmetic number, because the mean of its divisors is an integer number (322013829213).

Almost surely, 2^{1264202440561} is an apocalyptic number.

It is an amenable number.

1264202440561 is a deficient number, since it is larger than the sum of its proper divisors (23852876291).

1264202440561 is an equidigital number, since it uses as much as digits as its factorization.

1264202440561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23852876290.

The product of its (nonzero) digits is 92160, while the sum is 37.

The spelling of 1264202440561 in words is "one trillion, two hundred sixty-four billion, two hundred two million, four hundred forty thousand, five hundred sixty-one".