78157069 has 4 divisors (see below), whose sum is σ = 78238044. Its totient is φ = 78076096.

The previous prime is 78157049. The next prime is 78157073. The reversal of 78157069 is 96075187.

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

It can be written as a sum of positive squares in 2 ways, for example, as 41409225 + 36747844 = 6435^2 + 6062^2 .

It is a cyclic number.

It is not a de Polignac number, because 78157069 - 2⁷ = 78156941 is a prime.

It is a super-2 number, since 2×78157069² = 12217054869341522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78157049) 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 in 3 ways as a sum of consecutive naturals, for example, 39022 + ... + 40975.

It is an arithmetic number, because the mean of its divisors is an integer number (19559511).

Almost surely, 2^78157069 is an apocalyptic number.

It is an amenable number.

78157069 is a deficient number, since it is larger than the sum of its proper divisors (80975).

78157069 is an equidigital number, since it uses as much as digits as its factorization.

78157069 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80974.

The product of its (nonzero) digits is 105840, while the sum is 43.

The square root of 78157069 is about 8840.6486752953. The cubic root of 78157069 is about 427.5524717007.

It can be divided in two parts, 7815 and 7069, that added together give a square (14884 = 122²).

The spelling of 78157069 in words is "seventy-eight million, one hundred fifty-seven thousand, sixty-nine".