642722305 has 8 divisors (see below), whose sum is σ = 774269352. Its totient is φ = 512176128.

The previous prime is 642722263. The next prime is 642722309. The reversal of 642722305 is 503227246.

It can be written as a sum of positive squares in 4 ways, for example, as 466257649 + 176464656 = 21593^2 + 13284^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 642722305 - 2²⁹ = 105851393 is a prime.

It is a super-2 number, since 2×642722305² = 826183922689026050, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (642722309) 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, 248802 + ... + 251371.

It is an arithmetic number, because the mean of its divisors is an integer number (96783669).

Almost surely, 2^642722305 is an apocalyptic number.

It is an amenable number.

642722305 is a deficient number, since it is larger than the sum of its proper divisors (131547047).

642722305 is a wasteful number, since it uses less digits than its factorization.

642722305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 500435.

The product of its (nonzero) digits is 20160, while the sum is 31.

The square root of 642722305 is about 25351.9684640069. The cubic root of 642722305 is about 862.9940285322.

The spelling of 642722305 in words is "six hundred forty-two million, seven hundred twenty-two thousand, three hundred five".