129402281 has 4 divisors (see below), whose sum is σ = 131595600. Its totient is φ = 127208964.

The previous prime is 129402223. The next prime is 129402307. The reversal of 129402281 is 182204921.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 182204921 = 59 ⋅3088219.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-129402281 is a prime.

It is a super-2 number, since 2×129402281² = 33489900656005922, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (129402211) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1096571 + ... + 1096688.

It is an arithmetic number, because the mean of its divisors is an integer number (32898900).

Almost surely, 2^129402281 is an apocalyptic number.

It is an amenable number.

129402281 is a deficient number, since it is larger than the sum of its proper divisors (2193319).

129402281 is an equidigital number, since it uses as much as digits as its factorization.

129402281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2193318.

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 129402281 is about 11375.5123401102. The cubic root of 129402281 is about 505.8021184094.

The spelling of 129402281 in words is "one hundred twenty-nine million, four hundred two thousand, two hundred eighty-one".