102121221229861 has 2 divisors, whose sum is σ = 102121221229862. Its totient is φ = 102121221229860.

The previous prime is 102121221229817. The next prime is 102121221230023. The reversal of 102121221229861 is 168922122121201.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 101819703830625 + 301517399236 = 10090575^2 + 549106^2 .

It is a cyclic number.

It is not a de Polignac number, because 102121221229861 - 2⁴¹ = 99922197974309 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (102121221229801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51060610614930 + 51060610614931.

It is an arithmetic number, because the mean of its divisors is an integer number (51060610614931).

Almost surely, 2^{102121221229861} is an apocalyptic number.

It is an amenable number.

102121221229861 is a deficient number, since it is larger than the sum of its proper divisors (1).

102121221229861 is an equidigital number, since it uses as much as digits as its factorization.

102121221229861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 27648, while the sum is 40.

The spelling of 102121221229861 in words is "one hundred two trillion, one hundred twenty-one billion, two hundred twenty-one million, two hundred twenty-nine thousand, eight hundred sixty-one".