31729228129 has 3 divisors (see below), whose sum is σ = 31729406257. Its totient is φ = 31729050002.

The previous prime is 31729228061. The next prime is 31729228151. The reversal of 31729228129 is 92182292713.

It is a happy number.

The square root of 31729228129 is 178127.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 92182292713 = 7 ⋅13168898959.

It is not a de Polignac number, because 31729228129 - 2⁹ = 31729227617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31729228169) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 89064 + ... + 267190.

Almost surely, 2^31729228129 is an apocalyptic number.

31729228129 is the 178127-th square number.

31729228129 is the 89064-th centered octagonal number.

It is an amenable number.

31729228129 is a deficient number, since it is larger than the sum of its proper divisors (178128).

31729228129 is an frugal number, since it uses more digits than its factorization.

31729228129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 356254 (or 178127 counting only the distinct ones).

The product of its digits is 217728, while the sum is 46.

The spelling of 31729228129 in words is "thirty-one billion, seven hundred twenty-nine million, two hundred twenty-eight thousand, one hundred twenty-nine".