121647431621 has 2 divisors, whose sum is σ = 121647431622. Its totient is φ = 121647431620.

The previous prime is 121647431617. The next prime is 121647431663. The reversal of 121647431621 is 126134746121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 68107950625 + 53539480996 = 260975^2 + 231386^2 .

It is a cyclic number.

It is not a de Polignac number, because 121647431621 - 2² = 121647431617 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 (121647431821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60823715810 + 60823715811.

It is an arithmetic number, because the mean of its divisors is an integer number (60823715811).

Almost surely, 2^121647431621 is an apocalyptic number.

It is an amenable number.

121647431621 is a deficient number, since it is larger than the sum of its proper divisors (1).

121647431621 is an equidigital number, since it uses as much as digits as its factorization.

121647431621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 48384, while the sum is 38.

The spelling of 121647431621 in words is "one hundred twenty-one billion, six hundred forty-seven million, four hundred thirty-one thousand, six hundred twenty-one".