78252779 has 4 divisors (see below), whose sum is σ = 85366680. Its totient is φ = 71138880.

The previous prime is 78252767. The next prime is 78252781. The reversal of 78252779 is 97725287.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 78252779 - 2⁸ = 78252523 is a prime.

It is a super-2 number, since 2×78252779² = 12246994842445682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78252799) 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 in 3 ways as a sum of consecutive naturals, for example, 3556934 + ... + 3556955.

It is an arithmetic number, because the mean of its divisors is an integer number (21341670).

Almost surely, 2^78252779 is an apocalyptic number.

78252779 is a deficient number, since it is larger than the sum of its proper divisors (7113901).

78252779 is a wasteful number, since it uses less digits than its factorization.

78252779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7113900.

The product of its digits is 493920, while the sum is 47.

The square root of 78252779 is about 8846.0600834496. The cubic root of 78252779 is about 427.7269253370.

The spelling of 78252779 in words is "seventy-eight million, two hundred fifty-two thousand, seven hundred seventy-nine".