643664142 has 48 divisors (see below), whose sum is σ = 1523311920. Its totient is φ = 194803200.

The previous prime is 643664137. The next prime is 643664221. The reversal of 643664142 is 241466346.

643664142 is a `hidden beast` number, since 6 + 4 + 3 + 6 + 641 + 4 + 2 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 643664097 and 643664106.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 210142 + ... + 213182.

It is an arithmetic number, because the mean of its divisors is an integer number (31735665).

Almost surely, 2^643664142 is an apocalyptic number.

643664142 is an abundant number, since it is smaller than the sum of its proper divisors (879647778).

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

643664142 is a wasteful number, since it uses less digits than its factorization.

643664142 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4129 (or 4126 counting only the distinct ones).

The product of its digits is 82944, while the sum is 36.

The square root of 643664142 is about 25370.5368882884. The cubic root of 643664142 is about 863.4153629101.

The spelling of 643664142 in words is "six hundred forty-three million, six hundred sixty-four thousand, one hundred forty-two".