78907690 has 8 divisors (see below), whose sum is σ = 142033860. Its totient is φ = 31563072.

The previous prime is 78907681. The next prime is 78907691. The reversal of 78907690 is 9670987.

It is a Cunningham number, because it is equal to 8883²+1.

It can be written as a sum of positive squares in 2 ways, for example, as 78907689 + 1 = 8883^2 + 1^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×78907690² = 12452847082272200, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a self number, because there is not a number n which added to its sum of digits gives 78907690.

It is not an unprimeable number, because it can be changed into a prime (78907691) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3945375 + ... + 3945394.

Almost surely, 2^78907690 is an apocalyptic number.

78907690 is a deficient number, since it is larger than the sum of its proper divisors (63126170).

78907690 is a wasteful number, since it uses less digits than its factorization.

78907690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7890776.

The product of its (nonzero) digits is 190512, while the sum is 46.

The square root of 78907690 is about 8883.0000562873. Note that the first 4 decimals coincide. The cubic root of 78907690 is about 428.9168520471.

It can be divided in two parts, 78907 and 690, that added together give a palindrome (79597).

The spelling of 78907690 in words is "seventy-eight million, nine hundred seven thousand, six hundred ninety".