642650105 has 4 divisors (see below), whose sum is σ = 771180132. Its totient is φ = 514120080.

The previous prime is 642650101. The next prime is 642650143. The reversal of 642650105 is 501056246.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 501056246 = 2 ⋅250528123.

It can be written as a sum of positive squares in 2 ways, for example, as 70627216 + 572022889 = 8404^2 + 23917^2 .

It is not a de Polignac number, because 642650105 - 2² = 642650101 is a prime.

It is a super-2 number, since 2×642650105² = 825998314913022050, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (642650101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64265006 + ... + 64265015.

It is an arithmetic number, because the mean of its divisors is an integer number (192795033).

Almost surely, 2^642650105 is an apocalyptic number.

It is an amenable number.

642650105 is a deficient number, since it is larger than the sum of its proper divisors (128530027).

642650105 is a wasteful number, since it uses less digits than its factorization.

642650105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128530026.

The product of its (nonzero) digits is 7200, while the sum is 29.

The square root of 642650105 is about 25350.5444714704. The cubic root of 642650105 is about 862.9617126047.

The spelling of 642650105 in words is "six hundred forty-two million, six hundred fifty thousand, one hundred five".