643219992 has 48 divisors (see below), whose sum is σ = 1798255680. Its totient is φ = 207489600.

The previous prime is 643219991. The next prime is 643220003. The reversal of 643219992 is 299912346.

It is a happy number.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643219991) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 141859 + ... + 146322.

It is an arithmetic number, because the mean of its divisors is an integer number (37463660).

Almost surely, 2^643219992 is an apocalyptic number.

643219992 is a gapful number since it is divisible by the number (62) formed by its first and last digit.

It is an amenable number.

643219992 is an abundant number, since it is smaller than the sum of its proper divisors (1155035688).

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

643219992 is a wasteful number, since it uses less digits than its factorization.

643219992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 288224 (or 288217 counting only the distinct ones).

The product of its digits is 209952, while the sum is 45.

The square root of 643219992 is about 25361.7821140392. The cubic root of 643219992 is about 863.2167219584.

The spelling of 643219992 in words is "six hundred forty-three million, two hundred nineteen thousand, nine hundred ninety-two".