129811841 has 2 divisors, whose sum is σ = 129811842. Its totient is φ = 129811840.

The previous prime is 129811837. The next prime is 129811909. The reversal of 129811841 is 148118921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 84640000 + 45171841 = 9200^2 + 6721^2 .

It is a cyclic number.

It is not a de Polignac number, because 129811841 - 2² = 129811837 is a prime.

It is a super-2 number, since 2×129811841² = 33702228127618562, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (129811441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64905920 + 64905921.

It is an arithmetic number, because the mean of its divisors is an integer number (64905921).

Almost surely, 2^129811841 is an apocalyptic number.

It is an amenable number.

129811841 is a deficient number, since it is larger than the sum of its proper divisors (1).

129811841 is an equidigital number, since it uses as much as digits as its factorization.

129811841 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4608, while the sum is 35.

The square root of 129811841 is about 11393.4999451442. The cubic root of 129811841 is about 506.3351799769.

The spelling of 129811841 in words is "one hundred twenty-nine million, eight hundred eleven thousand, eight hundred forty-one".