129566420 has 24 divisors (see below), whose sum is σ = 273228648. Its totient is φ = 51609600.

The previous prime is 129566389. The next prime is 129566431. The reversal of 129566420 is 24665921.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 41319184 + 88247236 = 6428^2 + 9394^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8621 + ... + 18260.

It is an arithmetic number, because the mean of its divisors is an integer number (11384527).

Almost surely, 2^129566420 is an apocalyptic number.

129566420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129566420 is an abundant number, since it is smaller than the sum of its proper divisors (143662228).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

129566420 is a wasteful number, since it uses less digits than its factorization.

129566420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27131 (or 27129 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 129566420 is about 11382.7246298942. The cubic root of 129566420 is about 506.0158878918.

The spelling of 129566420 in words is "one hundred twenty-nine million, five hundred sixty-six thousand, four hundred twenty".