129723091 has 2 divisors, whose sum is σ = 129723092. Its totient is φ = 129723090.

The previous prime is 129723079. The next prime is 129723109. The reversal of 129723091 is 190327921.

It is a happy number.

Together with next prime (129723109) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 129723091 - 2⁷ = 129722963 is a prime.

It is not a weakly prime, because it can be changed into another prime (129723031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64861545 + 64861546.

It is an arithmetic number, because the mean of its divisors is an integer number (64861546).

Almost surely, 2^129723091 is an apocalyptic number.

129723091 is a deficient number, since it is larger than the sum of its proper divisors (1).

129723091 is an equidigital number, since it uses as much as digits as its factorization.

129723091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6804, while the sum is 34.

The square root of 129723091 is about 11389.6045146440. The cubic root of 129723091 is about 506.2197629454.

It can be divided in two parts, 1297230 and 91, that added together give a square (1297321 = 1139²).

The spelling of 129723091 in words is "one hundred twenty-nine million, seven hundred twenty-three thousand, ninety-one".