642646465 has 8 divisors (see below), whose sum is σ = 785726568. Its totient is φ = 504416640.

The previous prime is 642646453. The next prime is 642646493. The reversal of 642646465 is 564646246.

It can be written as a sum of positive squares in 4 ways, for example, as 314565696 + 328080769 = 17736^2 + 18113^2 .

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

It is not a de Polignac number, because 642646465 - 2⁹ = 642645953 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1212276 + ... + 1212805.

It is an arithmetic number, because the mean of its divisors is an integer number (98215821).

Almost surely, 2^642646465 is an apocalyptic number.

It is an amenable number.

642646465 is a deficient number, since it is larger than the sum of its proper divisors (143080103).

642646465 is a wasteful number, since it uses less digits than its factorization.

642646465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2425139.

The product of its digits is 829440, while the sum is 43.

The square root of 642646465 is about 25350.4726780390. The cubic root of 642646465 is about 862.9600833166.

The spelling of 642646465 in words is "six hundred forty-two million, six hundred forty-six thousand, four hundred sixty-five".