78465437261 has 4 divisors (see below), whose sum is σ = 78466382172. Its totient is φ = 78464492352.

The previous prime is 78465437251. The next prime is 78465437263. The reversal of 78465437261 is 16273456487.

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 20333334025 + 58132103236 = 142595^2 + 241106^2 .

It is a cyclic number.

It is not a de Polignac number, because 78465437261 - 2³⁴ = 61285568077 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 (78465437263) 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, 334460 + ... + 518453.

It is an arithmetic number, because the mean of its divisors is an integer number (19616595543).

Almost surely, 2^78465437261 is an apocalyptic number.

It is an amenable number.

78465437261 is a deficient number, since it is larger than the sum of its proper divisors (944911).

78465437261 is an equidigital number, since it uses as much as digits as its factorization.

78465437261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 944910.

The product of its digits is 6773760, while the sum is 53.

The spelling of 78465437261 in words is "seventy-eight billion, four hundred sixty-five million, four hundred thirty-seven thousand, two hundred sixty-one".