1021161643 has 2 divisors, whose sum is σ = 1021161644. Its totient is φ = 1021161642.

The previous prime is 1021161641. The next prime is 1021161667. The reversal of 1021161643 is 3461611201.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1021161643 - 2¹ = 1021161641 is a prime.

It is a super-2 number, since 2×1021161643² = 2085542202268918898, which contains 22 as substring.

Together with 1021161641, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1021161641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510580821 + 510580822.

It is an arithmetic number, because the mean of its divisors is an integer number (510580822).

Almost surely, 2^1021161643 is an apocalyptic number.

1021161643 is a deficient number, since it is larger than the sum of its proper divisors (1).

1021161643 is an equidigital number, since it uses as much as digits as its factorization.

1021161643 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 1021161643 is about 31955.6198969759. The cubic root of 1021161643 is about 1007.0047006056.

Adding to 1021161643 its reverse (3461611201), we get a palindrome (4482772844).

The spelling of 1021161643 in words is "one billion, twenty-one million, one hundred sixty-one thousand, six hundred forty-three".