129820863506 has 16 divisors (see below), whose sum is σ = 194988381720. Its totient is φ = 64824779520.

The previous prime is 129820863503. The next prime is 129820863509. The reversal of 129820863506 is 605368028921.

It is an interprime number because it is at equal distance from previous prime (129820863503) and next prime (129820863509).

It can be written as a sum of positive squares in 4 ways, for example, as 122440507225 + 7380356281 = 349915^2 + 85909^2 .

It is a super-2 number, since 2×129820863506² (a number of 23 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (129820863503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7746296 + ... + 7763036.

Almost surely, 2^129820863506 is an apocalyptic number.

129820863506 is a deficient number, since it is larger than the sum of its proper divisors (65167518214).

129820863506 is a wasteful number, since it uses less digits than its factorization.

129820863506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21629.

The product of its (nonzero) digits is 1244160, while the sum is 50.

The spelling of 129820863506 in words is "one hundred twenty-nine billion, eight hundred twenty million, eight hundred sixty-three thousand, five hundred six".