121711616650561 has 12 divisors (see below), whose sum is σ = 142616352841668. Its totient is φ = 103562752013952.

The previous prime is 121711616650537. The next prime is 121711616650619. The reversal of 121711616650561 is 165056616117121.

It can be written as a sum of positive squares in 2 ways, for example, as 76229662521600 + 45481954128961 = 8730960^2 + 6744031^2 .

It is not a de Polignac number, because 121711616650561 - 2²¹ = 121711614553409 is a prime.

It is a super-2 number, since 2×121711616650561² (a number of 29 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121711616650531) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9065360236 + ... + 9065373661.

It is an arithmetic number, because the mean of its divisors is an integer number (11884696070139).

Almost surely, 2^{121711616650561} is an apocalyptic number.

It is an amenable number.

121711616650561 is a deficient number, since it is larger than the sum of its proper divisors (20904736191107).

121711616650561 is a wasteful number, since it uses less digits than its factorization.

121711616650561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18130734048 (or 18130734041 counting only the distinct ones).

The product of its (nonzero) digits is 453600, while the sum is 49.

The spelling of 121711616650561 in words is "one hundred twenty-one trillion, seven hundred eleven billion, six hundred sixteen million, six hundred fifty thousand, five hundred sixty-one".