121531455977 has 2 divisors, whose sum is σ = 121531455978. Its totient is φ = 121531455976.

The previous prime is 121531455883. The next prime is 121531456021. The reversal of 121531455977 is 779554135121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 112133898496 + 9397557481 = 334864^2 + 96941^2 .

It is an emirp because it is prime and its reverse (779554135121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 121531455977 - 2¹⁰ = 121531454953 is a prime.

It is not a weakly prime, because it can be changed into another prime (121531454977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60765727988 + 60765727989.

It is an arithmetic number, because the mean of its divisors is an integer number (60765727989).

Almost surely, 2^121531455977 is an apocalyptic number.

It is an amenable number.

121531455977 is a deficient number, since it is larger than the sum of its proper divisors (1).

121531455977 is an equidigital number, since it uses as much as digits as its factorization.

121531455977 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1323000, while the sum is 50.

The spelling of 121531455977 in words is "one hundred twenty-one billion, five hundred thirty-one million, four hundred fifty-five thousand, nine hundred seventy-seven".