78661783 has 2 divisors, whose sum is σ = 78661784. Its totient is φ = 78661782.

The previous prime is 78661769. The next prime is 78661841. The reversal of 78661783 is 38716687.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 78661783 - 2¹³ = 78653591 is a prime.

It is a super-2 number, since 2×78661783² = 12375352209478178, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78661763) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39330891 + 39330892.

It is an arithmetic number, because the mean of its divisors is an integer number (39330892).

Almost surely, 2^78661783 is an apocalyptic number.

78661783 is a deficient number, since it is larger than the sum of its proper divisors (1).

78661783 is an equidigital number, since it uses as much as digits as its factorization.

78661783 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 338688, while the sum is 46.

The square root of 78661783 is about 8869.1478170115. The cubic root of 78661783 is about 428.4708312514.

The spelling of 78661783 in words is "seventy-eight million, six hundred sixty-one thousand, seven hundred eighty-three".