642464817 has 4 divisors (see below), whose sum is σ = 856619760. Its totient is φ = 428309876.

The previous prime is 642464783. The next prime is 642464843. The reversal of 642464817 is 718464246.

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 a cyclic number.

It is not a de Polignac number, because 642464817 - 2¹⁰ = 642463793 is a prime.

It is a super-2 number, since 2×642464817² = 825522082165686978, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (642464117) 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, 107077467 + ... + 107077472.

It is an arithmetic number, because the mean of its divisors is an integer number (214154940).

Almost surely, 2^642464817 is an apocalyptic number.

It is an amenable number.

642464817 is a deficient number, since it is larger than the sum of its proper divisors (214154943).

642464817 is a wasteful number, since it uses less digits than its factorization.

642464817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214154942.

The product of its digits is 258048, while the sum is 42.

The square root of 642464817 is about 25346.8896908477. The cubic root of 642464817 is about 862.8787686523.

The spelling of 642464817 in words is "six hundred forty-two million, four hundred sixty-four thousand, eight hundred seventeen".