129223977 has 4 divisors (see below), whose sum is σ = 172298640. Its totient is φ = 86149316.

The previous prime is 129223973. The next prime is 129223979. The reversal of 129223977 is 779322921.

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 129223977 - 2² = 129223973 is a prime.

It is not an unprimeable number, because it can be changed into a prime (129223973) 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, 21537327 + ... + 21537332.

It is an arithmetic number, because the mean of its divisors is an integer number (43074660).

Almost surely, 2^129223977 is an apocalyptic number.

It is an amenable number.

129223977 is a deficient number, since it is larger than the sum of its proper divisors (43074663).

129223977 is an equidigital number, since it uses as much as digits as its factorization.

129223977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43074662.

The product of its digits is 95256, while the sum is 42.

The square root of 129223977 is about 11367.6724530574. The cubic root of 129223977 is about 505.5696959339.

The spelling of 129223977 in words is "one hundred twenty-nine million, two hundred twenty-three thousand, nine hundred seventy-seven".