78491579 has 2 divisors, whose sum is σ = 78491580. Its totient is φ = 78491578.

The previous prime is 78491573. The next prime is 78491591. The reversal of 78491579 is 97519487.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 78491579 - 2¹⁶ = 78426043 is a prime.

It is a super-3 number, since 3×78491579³ (a number of 25 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (78491573) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39245789 + 39245790.

It is an arithmetic number, because the mean of its divisors is an integer number (39245790).

Almost surely, 2^78491579 is an apocalyptic number.

78491579 is a deficient number, since it is larger than the sum of its proper divisors (1).

78491579 is an equidigital number, since it uses as much as digits as its factorization.

78491579 is an evil number, because the sum of its binary digits is even.

The product of its digits is 635040, while the sum is 50.

The square root of 78491579 is about 8859.5473360663. The cubic root of 78491579 is about 428.1615742921.

The spelling of 78491579 in words is "seventy-eight million, four hundred ninety-one thousand, five hundred seventy-nine".