642981049 has 4 divisors (see below), whose sum is σ = 649347300. Its totient is φ = 636614800.

The previous prime is 642981043. The next prime is 642981149. The reversal of 642981049 is 940189246.

642981049 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 940189246 = 2 ⋅470094623.

It can be written as a sum of positive squares in 2 ways, for example, as 617174649 + 25806400 = 24843^2 + 5080^2 .

It is a cyclic number.

It is not a de Polignac number, because 642981049 - 2²⁵ = 609426617 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 642980996 and 642981014.

It is not an unprimeable number, because it can be changed into a prime (642981043) 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, 3182974 + ... + 3183175.

It is an arithmetic number, because the mean of its divisors is an integer number (162336825).

Almost surely, 2^642981049 is an apocalyptic number.

It is an amenable number.

642981049 is a deficient number, since it is larger than the sum of its proper divisors (6366251).

642981049 is a wasteful number, since it uses less digits than its factorization.

642981049 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6366250.

The product of its (nonzero) digits is 124416, while the sum is 43.

The square root of 642981049 is about 25357.0709862161. The cubic root of 642981049 is about 863.1098196329.

It can be divided in two parts, 6429 and 81049, that added together give a palindrome (87478).

The spelling of 642981049 in words is "six hundred forty-two million, nine hundred eighty-one thousand, forty-nine".