642497305 has 4 divisors (see below), whose sum is σ = 770996772. Its totient is φ = 513997840.

The previous prime is 642497281. The next prime is 642497327. The reversal of 642497305 is 503794246.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 227315929 + 415181376 = 15077^2 + 20376^2 .

It is a de Polignac number, because none of the positive numbers 2^k-642497305 is a prime.

It is a super-3 number, since 3×642497305³ (a number of 27 digits) contains 333 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64249726 + ... + 64249735.

It is an arithmetic number, because the mean of its divisors is an integer number (192749193).

Almost surely, 2^642497305 is an apocalyptic number.

It is an amenable number.

642497305 is a deficient number, since it is larger than the sum of its proper divisors (128499467).

642497305 is a wasteful number, since it uses less digits than its factorization.

642497305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128499466.

The product of its (nonzero) digits is 181440, while the sum is 40.

The square root of 642497305 is about 25347.5305503317. The cubic root of 642497305 is about 862.8933130196.

The spelling of 642497305 in words is "six hundred forty-two million, four hundred ninety-seven thousand, three hundred five".