1221012212197 has 2 divisors, whose sum is σ = 1221012212198. Its totient is φ = 1221012212196.

The previous prime is 1221012212153. The next prime is 1221012212279. The reversal of 1221012212197 is 7912122101221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 755845927236 + 465166284961 = 869394^2 + 682031^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221012212197 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221012212137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610506106098 + 610506106099.

It is an arithmetic number, because the mean of its divisors is an integer number (610506106099).

Almost surely, 2^{1221012212197} is an apocalyptic number.

It is an amenable number.

1221012212197 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221012212197 is an equidigital number, since it uses as much as digits as its factorization.

1221012212197 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2016, while the sum is 31.

The spelling of 1221012212197 in words is "one trillion, two hundred twenty-one billion, twelve million, two hundred twelve thousand, one hundred ninety-seven".