129370781 has 12 divisors (see below), whose sum is σ = 135079776. Its totient is φ = 123887160.

The previous prime is 129370777. The next prime is 129370817. The reversal of 129370781 is 187073921.

It is not a de Polignac number, because 129370781 - 2² = 129370777 is a prime.

It is a super-2 number, since 2×129370781² = 33473597953099922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129370741) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 98330 + ... + 99636.

It is an arithmetic number, because the mean of its divisors is an integer number (11256648).

Almost surely, 2^129370781 is an apocalyptic number.

It is an amenable number.

129370781 is a deficient number, since it is larger than the sum of its proper divisors (5708995).

129370781 is a wasteful number, since it uses less digits than its factorization.

129370781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1472 (or 1441 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 38.

The square root of 129370781 is about 11374.1277028175. The cubic root of 129370781 is about 505.7610731265.

The spelling of 129370781 in words is "one hundred twenty-nine million, three hundred seventy thousand, seven hundred eighty-one".