1643354956 has 6 divisors (see below), whose sum is σ = 2875871180. Its totient is φ = 821677476.

The previous prime is 1643354893. The next prime is 1643354957. The reversal of 1643354956 is 6594533461.

It is a super-2 number, since 2×1643354956² = 5401231022819523872, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1643354957) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 205419366 + ... + 205419373.

Almost surely, 2^1643354956 is an apocalyptic number.

It is an amenable number.

1643354956 is a deficient number, since it is larger than the sum of its proper divisors (1232516224).

1643354956 is a wasteful number, since it uses less digits than its factorization.

1643354956 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 410838743 (or 410838741 counting only the distinct ones).

The product of its digits is 1166400, while the sum is 46.

The square root of 1643354956 is about 40538.3146664979. The cubic root of 1643354956 is about 1180.0773089251.

The spelling of 1643354956 in words is "one billion, six hundred forty-three million, three hundred fifty-four thousand, nine hundred fifty-six".