642841547077 has 4 divisors (see below), whose sum is σ = 642901878796. Its totient is φ = 642781215360.

The previous prime is 642841547057. The next prime is 642841547099. The reversal of 642841547077 is 770745148246.

It is a Cunningham number, because it is equal to 801774²+1.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 34393186116 + 608448360961 = 185454^2 + 780031^2 .

It is a cyclic number.

It is not a de Polignac number, because 642841547077 - 2³⁵ = 608481808709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642841547057) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30149874 + ... + 30171187.

It is an arithmetic number, because the mean of its divisors is an integer number (160725469699).

Almost surely, 2^642841547077 is an apocalyptic number.

It is an amenable number.

642841547077 is a deficient number, since it is larger than the sum of its proper divisors (60331719).

642841547077 is a wasteful number, since it uses less digits than its factorization.

642841547077 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60331718.

The product of its (nonzero) digits is 10536960, while the sum is 55.

The spelling of 642841547077 in words is "six hundred forty-two billion, eight hundred forty-one million, five hundred forty-seven thousand, seventy-seven".