642757122 has 96 divisors (see below), whose sum is σ = 1629074304. Its totient is φ = 179366400.

The previous prime is 642757121. The next prime is 642757153. The reversal of 642757122 is 221757246.

It is a happy number.

642757122 is a `hidden beast` number, since 64 + 2 + 7 + 571 + 22 = 666.

It is a super-3 number, since 3×642757122³ (a number of 27 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (642757121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1852153 + ... + 1852499.

It is an arithmetic number, because the mean of its divisors is an integer number (16969524).

Almost surely, 2^642757122 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 642757122, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (814537152).

642757122 is an abundant number, since it is smaller than the sum of its proper divisors (986317182).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

642757122 is a wasteful number, since it uses less digits than its factorization.

642757122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 664 (or 661 counting only the distinct ones).

The product of its digits is 47040, while the sum is 36.

The square root of 642757122 is about 25352.6551272248. The cubic root of 642757122 is about 863.0096113743.

The spelling of 642757122 in words is "six hundred forty-two million, seven hundred fifty-seven thousand, one hundred twenty-two".