1220331997 has 2 divisors, whose sum is σ = 1220331998. Its totient is φ = 1220331996.

The previous prime is 1220331991. The next prime is 1220332007. The reversal of 1220331997 is 7991330221.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 788149476 + 432182521 = 28074^2 + 20789^2 .

It is a cyclic number.

It is not a de Polignac number, because 1220331997 - 2³ = 1220331989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1220331991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610165998 + 610165999.

It is an arithmetic number, because the mean of its divisors is an integer number (610165999).

Almost surely, 2^1220331997 is an apocalyptic number.

It is an amenable number.

1220331997 is a deficient number, since it is larger than the sum of its proper divisors (1).

1220331997 is an equidigital number, since it uses as much as digits as its factorization.

1220331997 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20412, while the sum is 37.

The square root of 1220331997 is about 34933.2505930954. The cubic root of 1220331997 is about 1068.6266472228.

The spelling of 1220331997 in words is "one billion, two hundred twenty million, three hundred thirty-one thousand, nine hundred ninety-seven".