642112081 has 8 divisors (see below), whose sum is σ = 691868520. Its totient is φ = 592407552.

The previous prime is 642112069. The next prime is 642112099. The reversal of 642112081 is 180211246.

It can be written as a sum of positive squares in 4 ways, for example, as 26625600 + 615486481 = 5160^2 + 24809^2 .

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 642112081 - 2¹¹ = 642110033 is a prime.

It is a super-2 number, since 2×642112081² = 824615849132301122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (642112061) 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, 14961 + ... + 38833.

It is an arithmetic number, because the mean of its divisors is an integer number (86483565).

Almost surely, 2^642112081 is an apocalyptic number.

It is an amenable number.

642112081 is a deficient number, since it is larger than the sum of its proper divisors (49756439).

642112081 is a wasteful number, since it uses less digits than its factorization.

642112081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25955.

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 642112081 is about 25339.9305642300. The cubic root of 642112081 is about 862.7208227138.

The spelling of 642112081 in words is "six hundred forty-two million, one hundred twelve thousand, eighty-one".