121721615077 has 2 divisors, whose sum is σ = 121721615078. Its totient is φ = 121721615076.

The previous prime is 121721615063. The next prime is 121721615209. The reversal of 121721615077 is 770516127121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 95077255716 + 26644359361 = 308346^2 + 163231^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121721615077 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121721616077) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60860807538 + 60860807539.

It is an arithmetic number, because the mean of its divisors is an integer number (60860807539).

Almost surely, 2^121721615077 is an apocalyptic number.

It is an amenable number.

121721615077 is a deficient number, since it is larger than the sum of its proper divisors (1).

121721615077 is an equidigital number, since it uses as much as digits as its factorization.

121721615077 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 41160, while the sum is 40.

The spelling of 121721615077 in words is "one hundred twenty-one billion, seven hundred twenty-one million, six hundred fifteen thousand, seventy-seven".