102102021509 has 2 divisors, whose sum is σ = 102102021510. Its totient is φ = 102102021508.

The previous prime is 102102021503. The next prime is 102102021547. The reversal of 102102021509 is 905120201201.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 86068890625 + 16033130884 = 293375^2 + 126622^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-102102021509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (102102021503) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51051010754 + 51051010755.

It is an arithmetic number, because the mean of its divisors is an integer number (51051010755).

Almost surely, 2^102102021509 is an apocalyptic number.

It is an amenable number.

102102021509 is a deficient number, since it is larger than the sum of its proper divisors (1).

102102021509 is an equidigital number, since it uses as much as digits as its factorization.

102102021509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 360, while the sum is 23.

The spelling of 102102021509 in words is "one hundred two billion, one hundred two million, twenty-one thousand, five hundred nine".