1221211219957 has 2 divisors, whose sum is σ = 1221211219958. Its totient is φ = 1221211219956.

The previous prime is 1221211219903. The next prime is 1221211219961. The reversal of 1221211219957 is 7599121121221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1214384164081 + 6827055876 = 1101991^2 + 82626^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221211219957 - 2⁷ = 1221211219829 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221211219997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610605609978 + 610605609979.

It is an arithmetic number, because the mean of its divisors is an integer number (610605609979).

Almost surely, 2^{1221211219957} is an apocalyptic number.

It is an amenable number.

1221211219957 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221211219957 is an equidigital number, since it uses as much as digits as its factorization.

1221211219957 is an evil number, because the sum of its binary digits is even.

The product of its digits is 45360, while the sum is 43.

The spelling of 1221211219957 in words is "one trillion, two hundred twenty-one billion, two hundred eleven million, two hundred nineteen thousand, nine hundred fifty-seven".