642465250661 has 8 divisors (see below), whose sum is σ = 691904220504. Its totient is φ = 593028933120.

The previous prime is 642465250613. The next prime is 642465250681. The reversal of 642465250661 is 166052564246.

It can be written as a sum of positive squares in 4 ways, for example, as 148066422436 + 494398828225 = 384794^2 + 703135^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 642465250661 - 2¹⁴ = 642465234277 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 (642465250681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 144980 + ... + 1142781.

It is an arithmetic number, because the mean of its divisors is an integer number (86488027563).

Almost surely, 2^642465250661 is an apocalyptic number.

It is an amenable number.

642465250661 is a deficient number, since it is larger than the sum of its proper divisors (49438969843).

642465250661 is a wasteful number, since it uses less digits than its factorization.

642465250661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1326151.

The product of its (nonzero) digits is 2073600, while the sum is 47.

The spelling of 642465250661 in words is "six hundred forty-two billion, four hundred sixty-five million, two hundred fifty thousand, six hundred sixty-one".