646522426542261 has 4 divisors (see below), whose sum is σ = 862029902056352. Its totient is φ = 431014951028172.

The previous prime is 646522426542217. The next prime is 646522426542287. The reversal of 646522426542261 is 162245624225646.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 646522426542261 - 2⁶ = 646522426542197 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 (646522426582261) 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, 107753737757041 + ... + 107753737757046.

It is an arithmetic number, because the mean of its divisors is an integer number (215507475514088).

Almost surely, 2^{646522426542261} is an apocalyptic number.

It is an amenable number.

646522426542261 is a deficient number, since it is larger than the sum of its proper divisors (215507475514091).

646522426542261 is a wasteful number, since it uses less digits than its factorization.

646522426542261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215507475514090.

The product of its digits is 66355200, while the sum is 57.

The spelling of 646522426542261 in words is "six hundred forty-six trillion, five hundred twenty-two billion, four hundred twenty-six million, five hundred forty-two thousand, two hundred sixty-one".