121438271921 has 2 divisors, whose sum is σ = 121438271922. Its totient is φ = 121438271920.

The previous prime is 121438271881. The next prime is 121438271939. The reversal of 121438271921 is 129172834121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 118625136400 + 2813135521 = 344420^2 + 53039^2 .

It is an emirp because it is prime and its reverse (129172834121) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121438271921 is a prime.

It is not a weakly prime, because it can be changed into another prime (121438271821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60719135960 + 60719135961.

It is an arithmetic number, because the mean of its divisors is an integer number (60719135961).

Almost surely, 2^121438271921 is an apocalyptic number.

It is an amenable number.

121438271921 is a deficient number, since it is larger than the sum of its proper divisors (1).

121438271921 is an equidigital number, since it uses as much as digits as its factorization.

121438271921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 48384, while the sum is 41.

The spelling of 121438271921 in words is "one hundred twenty-one billion, four hundred thirty-eight million, two hundred seventy-one thousand, nine hundred twenty-one".