78773381 has 2 divisors, whose sum is σ = 78773382. Its totient is φ = 78773380.

The previous prime is 78773369. The next prime is 78773389. The reversal of 78773381 is 18337787.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77704225 + 1069156 = 8815^2 + 1034^2 .

It is a cyclic number.

It is not a de Polignac number, because 78773381 - 2²² = 74579077 is a prime.

It is a super-2 number, since 2×78773381² = 12410491108342322, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78773389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39386690 + 39386691.

It is an arithmetic number, because the mean of its divisors is an integer number (39386691).

Almost surely, 2^78773381 is an apocalyptic number.

It is an amenable number.

78773381 is a deficient number, since it is larger than the sum of its proper divisors (1).

78773381 is an equidigital number, since it uses as much as digits as its factorization.

78773381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 197568, while the sum is 44.

The square root of 78773381 is about 8875.4369469903. The cubic root of 78773381 is about 428.6733603207.

The spelling of 78773381 in words is "seventy-eight million, seven hundred seventy-three thousand, three hundred eighty-one".