78862681 has 2 divisors, whose sum is σ = 78862682. Its totient is φ = 78862680.

The previous prime is 78862669. The next prime is 78862697. The reversal of 78862681 is 18626887.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 78854400 + 8281 = 8880^2 + 91^2 .

It is an emirp because it is prime and its reverse (18626887) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 78862681 - 2⁹ = 78862169 is a prime.

It is a super-2 number, since 2×78862681² = 12438644909015522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78862601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39431340 + 39431341.

It is an arithmetic number, because the mean of its divisors is an integer number (39431341).

Almost surely, 2^78862681 is an apocalyptic number.

78862681 is the 5617-th centered pentagonal number.

It is an amenable number.

78862681 is a deficient number, since it is larger than the sum of its proper divisors (1).

78862681 is an equidigital number, since it uses as much as digits as its factorization.

78862681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 258048, while the sum is 46.

The square root of 78862681 is about 8880.4662602816. The cubic root of 78862681 is about 428.8352850485.

It can be divided in two parts, 7 and 8862681, that added together give a palindrome (8862688).

The spelling of 78862681 in words is "seventy-eight million, eight hundred sixty-two thousand, six hundred eighty-one".