642423457 has 8 divisors (see below), whose sum is σ = 715697640. Its totient is φ = 572557440.

The previous prime is 642423451. The next prime is 642423479. The reversal of 642423457 is 754324246.

It can be written as a sum of positive squares in 4 ways, for example, as 41977441 + 600446016 = 6479^2 + 24504^2 .

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

It is a de Polignac number, because none of the positive numbers 2^k-642423457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (642423451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 851644 + ... + 852397.

It is an arithmetic number, because the mean of its divisors is an integer number (89462205).

Almost surely, 2^642423457 is an apocalyptic number.

It is an amenable number.

642423457 is a deficient number, since it is larger than the sum of its proper divisors (73274183).

642423457 is a wasteful number, since it uses less digits than its factorization.

642423457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1704083.

The product of its digits is 161280, while the sum is 37.

The square root of 642423457 is about 25346.0737985196. The cubic root of 642423457 is about 862.8602517204.

The spelling of 642423457 in words is "six hundred forty-two million, four hundred twenty-three thousand, four hundred fifty-seven".