642721622 has 8 divisors (see below), whose sum is σ = 975698136. Its totient is φ = 317488912.

The previous prime is 642721613. The next prime is 642721627. The reversal of 642721622 is 226127246.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642721627) 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, 1935743 + ... + 1936074.

It is an arithmetic number, because the mean of its divisors is an integer number (121962267).

Almost surely, 2^642721622 is an apocalyptic number.

642721622 is a deficient number, since it is larger than the sum of its proper divisors (332976514).

642721622 is a wasteful number, since it uses less digits than its factorization.

642721622 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3871902.

The product of its digits is 16128, while the sum is 32.

The square root of 642721622 is about 25351.9549936489. The cubic root of 642721622 is about 862.9937228402.

Adding to 642721622 its reverse (226127246), we get a palindrome (868848868).

The spelling of 642721622 in words is "six hundred forty-two million, seven hundred twenty-one thousand, six hundred twenty-two".