1220011997 has 2 divisors, whose sum is σ = 1220011998. Its totient is φ = 1220011996.

The previous prime is 1220011981. The next prime is 1220012011. The reversal of 1220011997 is 7991100221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1071318361 + 148693636 = 32731^2 + 12194^2 .

It is a cyclic number.

It is not a de Polignac number, because 1220011997 - 2⁴ = 1220011981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1220011097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610005998 + 610005999.

It is an arithmetic number, because the mean of its divisors is an integer number (610005999).

Almost surely, 2^1220011997 is an apocalyptic number.

It is an amenable number.

1220011997 is a deficient number, since it is larger than the sum of its proper divisors (1).

1220011997 is an equidigital number, since it uses as much as digits as its factorization.

1220011997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2268, while the sum is 32.

The square root of 1220011997 is about 34928.6701292792. The cubic root of 1220011997 is about 1068.5332326377.

The spelling of 1220011997 in words is "one billion, two hundred twenty million, eleven thousand, nine hundred ninety-seven".