129722973 has 4 divisors (see below), whose sum is σ = 172963968. Its totient is φ = 86481980.

The previous prime is 129722969. The next prime is 129722987. The reversal of 129722973 is 379227921.

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: 379227921 = 3 ⋅126409307.

It is a cyclic number.

It is not a de Polignac number, because 129722973 - 2² = 129722969 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129722933) 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, 21620493 + ... + 21620498.

It is an arithmetic number, because the mean of its divisors is an integer number (43240992).

Almost surely, 2^129722973 is an apocalyptic number.

It is an amenable number.

129722973 is a deficient number, since it is larger than the sum of its proper divisors (43240995).

129722973 is an equidigital number, since it uses as much as digits as its factorization.

129722973 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43240994.

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

The square root of 129722973 is about 11389.5993344806. The cubic root of 129722973 is about 506.2196094544.

The spelling of 129722973 in words is "one hundred twenty-nine million, seven hundred twenty-two thousand, nine hundred seventy-three".