78253391 has 2 divisors, whose sum is σ = 78253392. Its totient is φ = 78253390.

The previous prime is 78253369. The next prime is 78253433. The reversal of 78253391 is 19335287.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 78253391 - 2¹⁰ = 78252367 is a prime.

It is a super-2 number, since 2×78253391² = 12247186405997762, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78253691) 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, 39126695 + 39126696.

It is an arithmetic number, because the mean of its divisors is an integer number (39126696).

Almost surely, 2^78253391 is an apocalyptic number.

78253391 is a deficient number, since it is larger than the sum of its proper divisors (1).

78253391 is an equidigital number, since it uses as much as digits as its factorization.

78253391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 45360, while the sum is 38.

The square root of 78253391 is about 8846.0946750529. The cubic root of 78253391 is about 427.7280403908.

The spelling of 78253391 in words is "seventy-eight million, two hundred fifty-three thousand, three hundred ninety-one".