642648846247 has 4 divisors (see below), whose sum is σ = 664809151320. Its totient is φ = 620488541176.

The previous prime is 642648846227. The next prime is 642648846277. The reversal of 642648846247 is 742648846246.

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

It is a cyclic number.

It is not a de Polignac number, because 642648846247 - 2¹⁵ = 642648813479 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 (642648846227) 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, 11080152493 + ... + 11080152550.

It is an arithmetic number, because the mean of its divisors is an integer number (166202287830).

Almost surely, 2^642648846247 is an apocalyptic number.

642648846247 is a deficient number, since it is larger than the sum of its proper divisors (22160305073).

642648846247 is a wasteful number, since it uses less digits than its factorization.

642648846247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22160305072.

The product of its digits is 99090432, while the sum is 61.

Subtracting 642648846247 from its reverse (742648846246), we obtain a palindrome (99999999999).

The spelling of 642648846247 in words is "six hundred forty-two billion, six hundred forty-eight million, eight hundred forty-six thousand, two hundred forty-seven".