129639553 has 4 divisors (see below), whose sum is σ = 131280640. Its totient is φ = 127998468.

The previous prime is 129639533. The next prime is 129639557. The reversal of 129639553 is 355936921.

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 129639553 - 2¹³ = 129631361 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129639557) 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, 820425 + ... + 820582.

It is an arithmetic number, because the mean of its divisors is an integer number (32820160).

Almost surely, 2^129639553 is an apocalyptic number.

It is an amenable number.

129639553 is a deficient number, since it is larger than the sum of its proper divisors (1641087).

129639553 is an equidigital number, since it uses as much as digits as its factorization.

129639553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1641086.

The product of its digits is 218700, while the sum is 43.

The square root of 129639553 is about 11385.9366325305. The cubic root of 129639553 is about 506.1110758771. Note that the first 3 decimals are identical.

The spelling of 129639553 in words is "one hundred twenty-nine million, six hundred thirty-nine thousand, five hundred fifty-three".