129991077 has 6 divisors (see below), whose sum is σ = 187764902. Its totient is φ = 86660712.

The previous prime is 129991073. The next prime is 129991093. The reversal of 129991077 is 770199921.

It can be written as a sum of positive squares in only one way, i.e., 129754881 + 236196 = 11391^2 + 486^2 .

It is not a de Polignac number, because 129991077 - 2² = 129991073 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129991073) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7221718 + ... + 7221735.

Almost surely, 2^129991077 is an apocalyptic number.

It is an amenable number.

129991077 is a deficient number, since it is larger than the sum of its proper divisors (57773825).

129991077 is a wasteful number, since it uses less digits than its factorization.

129991077 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14443459 (or 14443456 counting only the distinct ones).

The product of its (nonzero) digits is 71442, while the sum is 45.

The square root of 129991077 is about 11401.3629448413. The cubic root of 129991077 is about 506.5681113611.

The spelling of 129991077 in words is "one hundred twenty-nine million, nine hundred ninety-one thousand, seventy-seven".