1020331261 has 2 divisors, whose sum is σ = 1020331262. Its totient is φ = 1020331260.

The previous prime is 1020331259. The next prime is 1020331327. The reversal of 1020331261 is 1621330201.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 973065636 + 47265625 = 31194^2 + 6875^2 .

It is a cyclic number.

It is not a de Polignac number, because 1020331261 - 2¹ = 1020331259 is a prime.

Together with 1020331259, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1020331231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510165630 + 510165631.

It is an arithmetic number, because the mean of its divisors is an integer number (510165631).

Almost surely, 2^1020331261 is an apocalyptic number.

It is an amenable number.

1020331261 is a deficient number, since it is larger than the sum of its proper divisors (1).

1020331261 is an equidigital number, since it uses as much as digits as its factorization.

1020331261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 1020331261 is about 31942.6245164670. The cubic root of 1020331261 is about 1006.7316699371.

Adding to 1020331261 its reverse (1621330201), we get a palindrome (2641661462).

The spelling of 1020331261 in words is "one billion, twenty million, three hundred thirty-one thousand, two hundred sixty-one".