643775190 has 16 divisors (see below), whose sum is σ = 1545060528. Its totient is φ = 171673376.

The previous prime is 643775177. The next prime is 643775191. The reversal of 643775190 is 91577346.

It is a super-2 number, since 2×643775190² = 828892990519072200, which contains 22 as substring.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643775191) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10729557 + ... + 10729616.

It is an arithmetic number, because the mean of its divisors is an integer number (96566283).

Almost surely, 2^643775190 is an apocalyptic number.

643775190 is an abundant number, since it is smaller than the sum of its proper divisors (901285338).

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

643775190 is a wasteful number, since it uses less digits than its factorization.

643775190 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21459183.

The product of its (nonzero) digits is 158760, while the sum is 42.

The square root of 643775190 is about 25372.7253167649. The cubic root of 643775190 is about 863.4650135636.

The spelling of 643775190 in words is "six hundred forty-three million, seven hundred seventy-five thousand, one hundred ninety".