1301321981 has 2 divisors, whose sum is σ = 1301321982. Its totient is φ = 1301321980.

The previous prime is 1301321971. The next prime is 1301322007. The reversal of 1301321981 is 1891231031.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1106161081 + 195160900 = 33259^2 + 13970^2 .

It is a cyclic number.

It is not a de Polignac number, because 1301321981 - 2¹⁰ = 1301320957 is a prime.

It is a super-2 number, since 2×1301321981² = 3386877796467528722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1301321911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 650660990 + 650660991.

It is an arithmetic number, because the mean of its divisors is an integer number (650660991).

Almost surely, 2^1301321981 is an apocalyptic number.

It is an amenable number.

1301321981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1301321981 is an equidigital number, since it uses as much as digits as its factorization.

1301321981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 29.

The square root of 1301321981 is about 36073.8406743723. The cubic root of 1301321981 is about 1091.7627066164.

The spelling of 1301321981 in words is "one billion, three hundred one million, three hundred twenty-one thousand, nine hundred eighty-one".