129870311861 has 2 divisors, whose sum is σ = 129870311862. Its totient is φ = 129870311860.

The previous prime is 129870311833. The next prime is 129870311863. The reversal of 129870311861 is 168113078921.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 91769614225 + 38100697636 = 302935^2 + 195194^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-129870311861 is a prime.

Together with 129870311863, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (129870311863) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64935155930 + 64935155931.

It is an arithmetic number, because the mean of its divisors is an integer number (64935155931).

Almost surely, 2^129870311861 is an apocalyptic number.

It is an amenable number.

129870311861 is a deficient number, since it is larger than the sum of its proper divisors (1).

129870311861 is an equidigital number, since it uses as much as digits as its factorization.

129870311861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 145152, while the sum is 47.

The spelling of 129870311861 in words is "one hundred twenty-nine billion, eight hundred seventy million, three hundred eleven thousand, eight hundred sixty-one".