1262400013661 has 4 divisors (see below), whose sum is σ = 1336658838012. Its totient is φ = 1188141189312.

The previous prime is 1262400013607. The next prime is 1262400013687. The reversal of 1262400013661 is 1663100042621.

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 763089602500 + 499310411161 = 873550^2 + 706619^2 .

It is a cyclic number.

It is not a de Polignac number, because 1262400013661 - 2⁶ = 1262400013597 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1262400013261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 37129412150 + ... + 37129412183.

It is an arithmetic number, because the mean of its divisors is an integer number (334164709503).

Almost surely, 2^{1262400013661} is an apocalyptic number.

It is an amenable number.

1262400013661 is a deficient number, since it is larger than the sum of its proper divisors (74258824351).

1262400013661 is an equidigital number, since it uses as much as digits as its factorization.

1262400013661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74258824350.

The product of its (nonzero) digits is 10368, while the sum is 32.

The spelling of 1262400013661 in words is "one trillion, two hundred sixty-two billion, four hundred million, thirteen thousand, six hundred sixty-one".