77899999 has 2 divisors, whose sum is σ = 77900000. Its totient is φ = 77899998.

The previous prime is 77899963. The next prime is 77900051. The reversal of 77899999 is 99999877.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77899999 is a prime.

77899999 is a modest number, since divided by 9999 gives 7789 as remainder.

It is a plaindrome in base 10.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77899949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38949999 + 38950000.

It is an arithmetic number, because the mean of its divisors is an integer number (38950000).

Almost surely, 2^77899999 is an apocalyptic number.

77899999 is a deficient number, since it is larger than the sum of its proper divisors (1).

77899999 is an equidigital number, since it uses as much as digits as its factorization.

77899999 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23147208, while the sum is 67.

The square root of 77899999 is about 8826.0976087963. The cubic root of 77899999 is about 427.0831960045.

The spelling of 77899999 in words is "seventy-seven million, eight hundred ninety-nine thousand, nine hundred ninety-nine".