1203121981 has 2 divisors, whose sum is σ = 1203121982. Its totient is φ = 1203121980.

The previous prime is 1203121967. The next prime is 1203122003. The reversal of 1203121981 is 1891213021.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 816016356 + 387105625 = 28566^2 + 19675^2 .

It is a cyclic number.

It is not a de Polignac number, because 1203121981 - 2⁷ = 1203121853 is a prime.

It is a super-2 number, since 2×1203121981² = 2895005002330728722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1203121951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 601560990 + 601560991.

It is an arithmetic number, because the mean of its divisors is an integer number (601560991).

Almost surely, 2^1203121981 is an apocalyptic number.

It is an amenable number.

1203121981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1203121981 is an equidigital number, since it uses as much as digits as its factorization.

1203121981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 28.

The square root of 1203121981 is about 34686.0487948685. The cubic root of 1203121981 is about 1063.5793266645.

The spelling of 1203121981 in words is "one billion, two hundred three million, one hundred twenty-one thousand, nine hundred eighty-one".