643237070221 has 16 divisors (see below), whose sum is σ = 648560525184. Its totient is φ = 637937786304.

The previous prime is 643237070209. The next prime is 643237070227. The reversal of 643237070221 is 122070732346.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-643237070221 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 (643237070227) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 88682031 + ... + 88689283.

It is an arithmetic number, because the mean of its divisors is an integer number (40535032824).

Almost surely, 2^643237070221 is an apocalyptic number.

It is an amenable number.

643237070221 is a deficient number, since it is larger than the sum of its proper divisors (5323454963).

643237070221 is a wasteful number, since it uses less digits than its factorization.

643237070221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8820.

The product of its (nonzero) digits is 84672, while the sum is 37.

The spelling of 643237070221 in words is "six hundred forty-three billion, two hundred thirty-seven million, seventy thousand, two hundred twenty-one".