129737891 has 2 divisors, whose sum is σ = 129737892. Its totient is φ = 129737890.

The previous prime is 129737887. The next prime is 129737921. The reversal of 129737891 is 198737921.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 129737891 - 2² = 129737887 is a prime.

It is a super-2 number, since 2×129737891² = 33663840722255762, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (129737831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64868945 + 64868946.

It is an arithmetic number, because the mean of its divisors is an integer number (64868946).

Almost surely, 2^129737891 is an apocalyptic number.

129737891 is a deficient number, since it is larger than the sum of its proper divisors (1).

129737891 is an equidigital number, since it uses as much as digits as its factorization.

129737891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 190512, while the sum is 47.

The square root of 129737891 is about 11390.2542113862. The cubic root of 129737891 is about 506.2390136111.

The spelling of 129737891 in words is "one hundred twenty-nine million, seven hundred thirty-seven thousand, eight hundred ninety-one".