643155434 has 12 divisors (see below), whose sum is σ = 1018182114. Its totient is φ = 304652232.

The previous prime is 643155427. The next prime is 643155437. The reversal of 643155434 is 434551346.

It can be written as a sum of positive squares in only one way, i.e., 488277409 + 154878025 = 22097^2 + 12445^2 .

It is a junction number, because it is equal to n+sod(n) for n = 643155394 and 643155403.

It is not an unprimeable number, because it can be changed into a prime (643155437) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 444677 + ... + 446120.

Almost surely, 2^643155434 is an apocalyptic number.

643155434 is a deficient number, since it is larger than the sum of its proper divisors (375026680).

643155434 is a wasteful number, since it uses less digits than its factorization.

643155434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 890837 (or 890818 counting only the distinct ones).

The product of its digits is 86400, while the sum is 35.

The square root of 643155434 is about 25360.5093403110. The cubic root of 643155434 is about 863.1878415285.

The spelling of 643155434 in words is "six hundred forty-three million, one hundred fifty-five thousand, four hundred thirty-four".