78926581 has 2 divisors, whose sum is σ = 78926582. Its totient is φ = 78926580.

The previous prime is 78926473. The next prime is 78926633. The reversal of 78926581 is 18562987.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 49928356 + 28998225 = 7066^2 + 5385^2 .

It is a cyclic number.

It is not a de Polignac number, because 78926581 - 2¹¹ = 78924533 is a prime.

It is a super-2 number, since 2×78926581² = 12458810376699122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78921581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39463290 + 39463291.

It is an arithmetic number, because the mean of its divisors is an integer number (39463291).

Almost surely, 2^78926581 is an apocalyptic number.

It is an amenable number.

78926581 is a deficient number, since it is larger than the sum of its proper divisors (1).

78926581 is an equidigital number, since it uses as much as digits as its factorization.

78926581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 241920, while the sum is 46.

The square root of 78926581 is about 8884.0633158482. The cubic root of 78926581 is about 428.9510777849.

It can be divided in two parts, 78926 and 581, that added together give a cube (79507 = 43³).

The spelling of 78926581 in words is "seventy-eight million, nine hundred twenty-six thousand, five hundred eighty-one".