1221011017901 has 2 divisors, whose sum is σ = 1221011017902. Its totient is φ = 1221011017900.

The previous prime is 1221011017873. The next prime is 1221011017913. The reversal of 1221011017901 is 1097101101221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 777308485801 + 443702532100 = 881651^2 + 666110^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221011017901 - 2¹⁴ = 1221011001517 is a prime.

It is a super-2 number, since 2×1221011017901² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221011017981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610505508950 + 610505508951.

It is an arithmetic number, because the mean of its divisors is an integer number (610505508951).

Almost surely, 2^{1221011017901} is an apocalyptic number.

It is an amenable number.

1221011017901 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221011017901 is an equidigital number, since it uses as much as digits as its factorization.

1221011017901 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 252, while the sum is 26.

The spelling of 1221011017901 in words is "one trillion, two hundred twenty-one billion, eleven million, seventeen thousand, nine hundred one".