129086623421 has 4 divisors (see below), whose sum is σ = 147527569632. Its totient is φ = 110645677212.

The previous prime is 129086623361. The next prime is 129086623483. The reversal of 129086623421 is 124326680921.

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: 124326680921 = 191 ⋅650925031.

It is a de Polignac number, because none of the positive numbers 2^k-129086623421 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129086623121) 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, 9220473095 + ... + 9220473108.

It is an arithmetic number, because the mean of its divisors is an integer number (36881892408).

Almost surely, 2^129086623421 is an apocalyptic number.

It is an amenable number.

129086623421 is a deficient number, since it is larger than the sum of its proper divisors (18440946211).

129086623421 is an equidigital number, since it uses as much as digits as its factorization.

129086623421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18440946210.

The product of its (nonzero) digits is 248832, while the sum is 44.

The spelling of 129086623421 in words is "one hundred twenty-nine billion, eighty-six million, six hundred twenty-three thousand, four hundred twenty-one".