1021340981 has 2 divisors, whose sum is σ = 1021340982. Its totient is φ = 1021340980.

The previous prime is 1021340959. The next prime is 1021341043. The reversal of 1021340981 is 1890431201.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 765628900 + 255712081 = 27670^2 + 15991^2 .

It is a cyclic number.

It is not a de Polignac number, because 1021340981 - 2¹⁴ = 1021324597 is a prime.

It is a super-2 number, since 2×1021340981² = 2086274798940084722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1021340941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510670490 + 510670491.

It is an arithmetic number, because the mean of its divisors is an integer number (510670491).

Almost surely, 2^1021340981 is an apocalyptic number.

It is an amenable number.

1021340981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1021340981 is an equidigital number, since it uses as much as digits as its factorization.

1021340981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1728, while the sum is 29.

The square root of 1021340981 is about 31958.4258216828. The cubic root of 1021340981 is about 1007.0636477335.

The spelling of 1021340981 in words is "one billion, twenty-one million, three hundred forty thousand, nine hundred eighty-one".