101221099961 has 2 divisors, whose sum is σ = 101221099962. Its totient is φ = 101221099960.

The previous prime is 101221099943. The next prime is 101221099999. The reversal of 101221099961 is 169990122101.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 90026401936 + 11194698025 = 300044^2 + 105805^2 .

It is an emirp because it is prime and its reverse (169990122101) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 101221099961 - 2²⁶ = 101153991097 is a prime.

It is a super-2 number, since 2×101221099961² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (101221099261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50610549980 + 50610549981.

It is an arithmetic number, because the mean of its divisors is an integer number (50610549981).

Almost surely, 2^101221099961 is an apocalyptic number.

It is an amenable number.

101221099961 is a deficient number, since it is larger than the sum of its proper divisors (1).

101221099961 is an equidigital number, since it uses as much as digits as its factorization.

101221099961 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17496, while the sum is 41.

The spelling of 101221099961 in words is "one hundred one billion, two hundred twenty-one million, ninety-nine thousand, nine hundred sixty-one".