1643485531 has 2 divisors, whose sum is σ = 1643485532. Its totient is φ = 1643485530.

The previous prime is 1643485507. The next prime is 1643485567. The reversal of 1643485531 is 1355843461.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1643485531 - 2¹⁷ = 1643354459 is a prime.

It is a super-2 number, since 2×1643485531² = 5402089381212703922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1643485031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 821742765 + 821742766.

It is an arithmetic number, because the mean of its divisors is an integer number (821742766).

Almost surely, 2^1643485531 is an apocalyptic number.

1643485531 is a deficient number, since it is larger than the sum of its proper divisors (1).

1643485531 is an equidigital number, since it uses as much as digits as its factorization.

1643485531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 172800, while the sum is 40.

The square root of 1643485531 is about 40539.9251479329. The cubic root of 1643485531 is about 1180.1085629792.

The spelling of 1643485531 in words is "one billion, six hundred forty-three million, four hundred eighty-five thousand, five hundred thirty-one".