129784457 has 4 divisors (see below), whose sum is σ = 141583056. Its totient is φ = 117985860.

The previous prime is 129784453. The next prime is 129784471. The reversal of 129784457 is 754487921.

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.

It is a cyclic number.

It is not a de Polignac number, because 129784457 - 2² = 129784453 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129784453) 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, 5899283 + ... + 5899304.

It is an arithmetic number, because the mean of its divisors is an integer number (35395764).

Almost surely, 2^129784457 is an apocalyptic number.

It is an amenable number.

129784457 is a deficient number, since it is larger than the sum of its proper divisors (11798599).

129784457 is a wasteful number, since it uses less digits than its factorization.

129784457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11798598.

The product of its digits is 564480, while the sum is 47.

The square root of 129784457 is about 11392.2981439216. The cubic root of 129784457 is about 506.2995734211.

The spelling of 129784457 in words is "one hundred twenty-nine million, seven hundred eighty-four thousand, four hundred fifty-seven".