129971887 has 2 divisors, whose sum is σ = 129971888. Its totient is φ = 129971886.

The previous prime is 129971857. The next prime is 129971899. The reversal of 129971887 is 788179921.

It is a strong prime.

It is an emirp because it is prime and its reverse (788179921) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 129971887 - 2¹¹ = 129969839 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129971857) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64985943 + 64985944.

It is an arithmetic number, because the mean of its divisors is an integer number (64985944).

Almost surely, 2^129971887 is an apocalyptic number.

129971887 is a deficient number, since it is larger than the sum of its proper divisors (1).

129971887 is an equidigital number, since it uses as much as digits as its factorization.

129971887 is an evil number, because the sum of its binary digits is even.

The product of its digits is 508032, while the sum is 52.

The square root of 129971887 is about 11400.5213477279. The cubic root of 129971887 is about 506.5431826745.

It can be divided in two parts, 12997 and 1887, that added together give a square (14884 = 122²).

The spelling of 129971887 in words is "one hundred twenty-nine million, nine hundred seventy-one thousand, eight hundred eighty-seven".