643151101 has 4 divisors (see below), whose sum is σ = 646704604. Its totient is φ = 639597600.

The previous prime is 643151071. The next prime is 643151111. The reversal of 643151101 is 101151346.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 253128100 + 390023001 = 15910^2 + 19749^2 .

It is a cyclic number.

It is not a de Polignac number, because 643151101 - 2⁷ = 643150973 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643151111) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1776480 + ... + 1776841.

It is an arithmetic number, because the mean of its divisors is an integer number (161676151).

Almost surely, 2^643151101 is an apocalyptic number.

It is an amenable number.

643151101 is a deficient number, since it is larger than the sum of its proper divisors (3553503).

643151101 is a wasteful number, since it uses less digits than its factorization.

643151101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3553502.

The product of its (nonzero) digits is 360, while the sum is 22.

The square root of 643151101 is about 25360.4239120721. The cubic root of 643151101 is about 863.1859030643.

The spelling of 643151101 in words is "six hundred forty-three million, one hundred fifty-one thousand, one hundred one".