79781563 has 2 divisors, whose sum is σ = 79781564. Its totient is φ = 79781562.

The previous prime is 79781543. The next prime is 79781573. The reversal of 79781563 is 36518797.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-79781563 is a prime.

It is not a weakly prime, because it can be changed into another prime (79781543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39890781 + 39890782.

It is an arithmetic number, because the mean of its divisors is an integer number (39890782).

Almost surely, 2^79781563 is an apocalyptic number.

79781563 is a deficient number, since it is larger than the sum of its proper divisors (1).

79781563 is an equidigital number, since it uses as much as digits as its factorization.

79781563 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 317520, while the sum is 46.

The square root of 79781563 is about 8932.0525636608. The cubic root of 79781563 is about 430.4944069836.

The spelling of 79781563 in words is "seventy-nine million, seven hundred eighty-one thousand, five hundred sixty-three".