78808581 has 6 divisors (see below), whose sum is σ = 113834630. Its totient is φ = 52539048.

The previous prime is 78808507. The next prime is 78808591. The reversal of 78808581 is 18580887.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 55130625 + 23677956 = 7425^2 + 4866^2 .

It is not a de Polignac number, because 78808581 - 2¹⁰ = 78807557 is a prime.

It is a super-2 number, since 2×78808581² = 12421584878467122, 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 (78808501) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4378246 + ... + 4378263.

Almost surely, 2^78808581 is an apocalyptic number.

It is an amenable number.

78808581 is a deficient number, since it is larger than the sum of its proper divisors (35026049).

78808581 is a wasteful number, since it uses less digits than its factorization.

78808581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8756515 (or 8756512 counting only the distinct ones).

The product of its (nonzero) digits is 143360, while the sum is 45.

The square root of 78808581 is about 8877.4197264746. The cubic root of 78808581 is about 428.7372019175.

It can be divided in two parts, 7880 and 8581, that added together give a palindrome (16461).

The spelling of 78808581 in words is "seventy-eight million, eight hundred eight thousand, five hundred eighty-one".