80661599 has 2 divisors, whose sum is σ = 80661600. Its totient is φ = 80661598.

The previous prime is 80661587. The next prime is 80661613. The reversal of 80661599 is 99516608.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-80661599 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (80661799) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40330799 + 40330800.

It is an arithmetic number, because the mean of its divisors is an integer number (40330800).

Almost surely, 2^80661599 is an apocalyptic number.

80661599 is a deficient number, since it is larger than the sum of its proper divisors (1).

80661599 is an equidigital number, since it uses as much as digits as its factorization.

80661599 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 116640, while the sum is 44.

The square root of 80661599 is about 8981.1802676486. The cubic root of 80661599 is about 432.0714884408.

The spelling of 80661599 in words is "eighty million, six hundred sixty-one thousand, five hundred ninety-nine".