129668787537 has 4 divisors (see below), whose sum is σ = 172891716720. Its totient is φ = 86445858356.

The previous prime is 129668787517. The next prime is 129668787539. The reversal of 129668787537 is 735787866921.

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: 735787866921 = 3 ⋅245262622307.

It is a cyclic number.

It is not a de Polignac number, because 129668787537 - 2²³ = 129660398929 is a prime.

It is a super-2 number, since 2×129668787537² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (129668787539) 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 3 ways as a sum of consecutive naturals, for example, 21611464587 + ... + 21611464592.

It is an arithmetic number, because the mean of its divisors is an integer number (43222929180).

Almost surely, 2^129668787537 is an apocalyptic number.

It is an amenable number.

129668787537 is a deficient number, since it is larger than the sum of its proper divisors (43222929183).

129668787537 is an equidigital number, since it uses as much as digits as its factorization.

129668787537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43222929182.

The product of its digits is 213373440, while the sum is 69.

The spelling of 129668787537 in words is "one hundred twenty-nine billion, six hundred sixty-eight million, seven hundred eighty-seven thousand, five hundred thirty-seven".