1221011220061 has 2 divisors, whose sum is σ = 1221011220062. Its totient is φ = 1221011220060.

The previous prime is 1221011220043. The next prime is 1221011220127. The reversal of 1221011220061 is 1600221101221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 991579799961 + 229431420100 = 995781^2 + 478990^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221011220061 - 2⁵ = 1221011220029 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221011220001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610505610030 + 610505610031.

It is an arithmetic number, because the mean of its divisors is an integer number (610505610031).

Almost surely, 2^{1221011220061} is an apocalyptic number.

It is an amenable number.

1221011220061 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221011220061 is an equidigital number, since it uses as much as digits as its factorization.

1221011220061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96, while the sum is 19.

Adding to 1221011220061 its reverse (1600221101221), we get a palindrome (2821232321282).

The spelling of 1221011220061 in words is "one trillion, two hundred twenty-one billion, eleven million, two hundred twenty thousand, sixty-one".