78573947261 has 4 divisors (see below), whose sum is σ = 78577890300. Its totient is φ = 78570004224.

The previous prime is 78573947251. The next prime is 78573947297. The reversal of 78573947261 is 16274937587.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16274937587 = 577 ⋅28206131.

It can be written as a sum of positive squares in 2 ways, for example, as 52718915236 + 25855032025 = 229606^2 + 160795^2 .

It is a cyclic number.

It is not a de Polignac number, because 78573947261 - 2³⁴ = 61394078077 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 78573947261.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78573947201) 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, 1941476 + ... + 1981533.

It is an arithmetic number, because the mean of its divisors is an integer number (19644472575).

Almost surely, 2^78573947261 is an apocalyptic number.

It is an amenable number.

78573947261 is a deficient number, since it is larger than the sum of its proper divisors (3943039).

78573947261 is a wasteful number, since it uses less digits than its factorization.

78573947261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3943038.

The product of its digits is 17781120, while the sum is 59.

The spelling of 78573947261 in words is "seventy-eight billion, five hundred seventy-three million, nine hundred forty-seven thousand, two hundred sixty-one".