102621617021909 has 2 divisors, whose sum is σ = 102621617021910. Its totient is φ = 102621617021908.

The previous prime is 102621617021897. The next prime is 102621617021947. The reversal of 102621617021909 is 909120716126201.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 59840899776100 + 42780717245809 = 7735690^2 + 6540697^2 .

It is a cyclic number.

It is not a de Polignac number, because 102621617021909 - 2¹⁶ = 102621616956373 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (102621617021009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51310808510954 + 51310808510955.

It is an arithmetic number, because the mean of its divisors is an integer number (51310808510955).

Almost surely, 2^{102621617021909} is an apocalyptic number.

It is an amenable number.

102621617021909 is a deficient number, since it is larger than the sum of its proper divisors (1).

102621617021909 is an equidigital number, since it uses as much as digits as its factorization.

102621617021909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 163296, while the sum is 47.

The spelling of 102621617021909 in words is "one hundred two trillion, six hundred twenty-one billion, six hundred seventeen million, twenty-one thousand, nine hundred nine".