129666420 has 240 divisors, whose sum is σ = 450793728. Its totient is φ = 31000320.

The previous prime is 129666403. The next prime is 129666421. The reversal of 129666420 is 24666921.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129666421) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 989755 + ... + 989885.

Almost surely, 2^129666420 is an apocalyptic number.

129666420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 129666420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (225396864).

129666420 is an abundant number, since it is smaller than the sum of its proper divisors (321127308).

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

129666420 is a wasteful number, since it uses less digits than its factorization.

129666420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 212 (or 201 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 129666420 is about 11387.1164040770. The cubic root of 129666420 is about 506.1460362646.

The spelling of 129666420 in words is "one hundred twenty-nine million, six hundred sixty-six thousand, four hundred twenty".