643363650 has 36 divisors (see below), whose sum is σ = 1728504882. Its totient is φ = 171563520.

The previous prime is 643363649. The next prime is 643363703. The reversal of 643363650 is 56363346.

It is a happy number.

643363650 is a `hidden beast` number, since 643 + 3 + 6 + 3 + 6 + 5 + 0 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 496977849 + 146385801 = 22293^2 + 12099^2 .

It is a super-2 number, since 2×643363650² = 827833572282645000, which contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 714399 + ... + 715298.

Almost surely, 2^643363650 is an apocalyptic number.

643363650 is an abundant number, since it is smaller than the sum of its proper divisors (1085141232).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

643363650 is a wasteful number, since it uses less digits than its factorization.

643363650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1429715 (or 1429707 counting only the distinct ones).

The product of its (nonzero) digits is 116640, while the sum is 36.

The square root of 643363650 is about 25364.6141307137. The cubic root of 643363650 is about 863.2809813400.

The spelling of 643363650 in words is "six hundred forty-three million, three hundred sixty-three thousand, six hundred fifty".