129825769 has 4 divisors (see below), whose sum is σ = 129854340. Its totient is φ = 129797200.

The previous prime is 129825739. The next prime is 129825791. The reversal of 129825769 is 967528921.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 967528921 = 683 ⋅1416587.

It can be written as a sum of positive squares in 2 ways, for example, as 89019225 + 40806544 = 9435^2 + 6388^2 .

It is a cyclic number.

It is not a de Polignac number, because 129825769 - 2¹¹ = 129823721 is a prime.

It is a super-2 number, since 2×129825769² = 33709460592882722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129825739) 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, 5782 + ... + 17119.

It is an arithmetic number, because the mean of its divisors is an integer number (32463585).

Almost surely, 2^129825769 is an apocalyptic number.

It is an amenable number.

129825769 is a deficient number, since it is larger than the sum of its proper divisors (28571).

129825769 is an equidigital number, since it uses as much as digits as its factorization.

129825769 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28570.

The product of its digits is 544320, while the sum is 49.

The square root of 129825769 is about 11394.1111544517. Note that the first 4 decimals coincide. The cubic root of 129825769 is about 506.3532881970.

The spelling of 129825769 in words is "one hundred twenty-nine million, eight hundred twenty-five thousand, seven hundred sixty-nine".