78531377 has 2 divisors, whose sum is σ = 78531378. Its totient is φ = 78531376.

The previous prime is 78531367. The next prime is 78531379. The reversal of 78531377 is 77313587.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 78304801 + 226576 = 8849^2 + 476^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78531377 is a prime.

It is a super-2 number, since 2×78531377² = 12334354347032258, which contains 22 as substring.

Together with 78531379, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (78531379) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39265688 + 39265689.

It is an arithmetic number, because the mean of its divisors is an integer number (39265689).

Almost surely, 2^78531377 is an apocalyptic number.

It is an amenable number.

78531377 is a deficient number, since it is larger than the sum of its proper divisors (1).

78531377 is an equidigital number, since it uses as much as digits as its factorization.

78531377 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 123480, while the sum is 41.

The square root of 78531377 is about 8861.7931029787. The cubic root of 78531377 is about 428.2339264068.

The spelling of 78531377 in words is "seventy-eight million, five hundred thirty-one thousand, three hundred seventy-seven".