212220109956661 has 2 divisors, whose sum is σ = 212220109956662. Its totient is φ = 212220109956660.

The previous prime is 212220109956643. The next prime is 212220109956689. The reversal of 212220109956661 is 166659901022212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 198844010654436 + 13376099302225 = 14101206^2 + 3657335^2 .

It is a cyclic number.

It is not a de Polignac number, because 212220109956661 - 2²⁷ = 212219975738933 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 212220109956599 and 212220109956608.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212220109956761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106110054978330 + 106110054978331.

It is an arithmetic number, because the mean of its divisors is an integer number (106110054978331).

Almost surely, 2^{212220109956661} is an apocalyptic number.

It is an amenable number.

212220109956661 is a deficient number, since it is larger than the sum of its proper divisors (1).

212220109956661 is an equidigital number, since it uses as much as digits as its factorization.

212220109956661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1399680, while the sum is 52.

The spelling of 212220109956661 in words is "two hundred twelve trillion, two hundred twenty billion, one hundred nine million, nine hundred fifty-six thousand, six hundred sixty-one".