102129991 has 2 divisors, whose sum is σ = 102129992. Its totient is φ = 102129990.

The previous prime is 102129983. The next prime is 102130037. The reversal of 102129991 is 199921201.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 102129991 - 2³ = 102129983 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (102129961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51064995 + 51064996.

It is an arithmetic number, because the mean of its divisors is an integer number (51064996).

Almost surely, 2^102129991 is an apocalyptic number.

102129991 is a deficient number, since it is larger than the sum of its proper divisors (1).

102129991 is an equidigital number, since it uses as much as digits as its factorization.

102129991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2916, while the sum is 34.

The square root of 102129991 is about 10105.9384027412. The cubic root of 102129991 is about 467.4312724614.

The spelling of 102129991 in words is "one hundred two million, one hundred twenty-nine thousand, nine hundred ninety-one".