78261311 has 2 divisors, whose sum is σ = 78261312. Its totient is φ = 78261310.

The previous prime is 78261299. The next prime is 78261331. The reversal of 78261311 is 11316287.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78261311 is a prime.

It is a super-3 number, since 3×78261311³ (a number of 25 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78261331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39130655 + 39130656.

It is an arithmetic number, because the mean of its divisors is an integer number (39130656).

Almost surely, 2^78261311 is an apocalyptic number.

78261311 is a deficient number, since it is larger than the sum of its proper divisors (1).

78261311 is an equidigital number, since it uses as much as digits as its factorization.

78261311 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2016, while the sum is 29.

The square root of 78261311 is about 8846.5423188950. The cubic root of 78261311 is about 427.7424699755.

Adding to 78261311 its reverse (11316287), we get a palindrome (89577598).

The spelling of 78261311 in words is "seventy-eight million, two hundred sixty-one thousand, three hundred eleven".