642661201 has 24 divisors (see below), whose sum is σ = 798992640. Its totient is φ = 506128896.

The previous prime is 642661189. The next prime is 642661207. The reversal of 642661201 is 102166246.

642661201 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 642661201 - 2²¹ = 640564049 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 642661201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642661207) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 281601 + ... + 283873.

It is an arithmetic number, because the mean of its divisors is an integer number (33291360).

Almost surely, 2^642661201 is an apocalyptic number.

It is an amenable number.

642661201 is a deficient number, since it is larger than the sum of its proper divisors (156331439).

642661201 is a wasteful number, since it uses less digits than its factorization.

642661201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2545 (or 2532 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 642661201 is about 25350.7633218410. The cubic root of 642661201 is about 862.9666792099.

The spelling of 642661201 in words is "six hundred forty-two million, six hundred sixty-one thousand, two hundred one".