129420561 has 8 divisors (see below), whose sum is σ = 177224704. Its totient is φ = 83948400.

The previous prime is 129420553. The next prime is 129420569. The reversal of 129420561 is 165024921.

It is an interprime number because it is at equal distance from previous prime (129420553) and next prime (129420569).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 129420561 - 2³ = 129420553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129420569) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 582865 + ... + 583086.

It is an arithmetic number, because the mean of its divisors is an integer number (22153088).

Almost surely, 2^129420561 is an apocalyptic number.

It is an amenable number.

129420561 is a deficient number, since it is larger than the sum of its proper divisors (47804143).

129420561 is a wasteful number, since it uses less digits than its factorization.

129420561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1165991.

The product of its (nonzero) digits is 4320, while the sum is 30.

The square root of 129420561 is about 11376.3157920304. The cubic root of 129420561 is about 505.8259346495.

The spelling of 129420561 in words is "one hundred twenty-nine million, four hundred twenty thousand, five hundred sixty-one".