1642653709 has 4 divisors (see below), whose sum is σ = 1642859260. Its totient is φ = 1642448160.

The previous prime is 1642653703. The next prime is 1642653731. The reversal of 1642653709 is 9073562461.

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 701084484 + 941569225 = 26478^2 + 30685^2 .

It is a cyclic number.

It is not a de Polignac number, because 1642653709 - 2⁹ = 1642653197 is a prime.

It is a super-2 number, since 2×1642653709² = 5396622415382913362, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1642653703) 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, 90282 + ... + 106939.

It is an arithmetic number, because the mean of its divisors is an integer number (410714815).

Almost surely, 2^1642653709 is an apocalyptic number.

It is an amenable number.

1642653709 is a deficient number, since it is larger than the sum of its proper divisors (205551).

1642653709 is an equidigital number, since it uses as much as digits as its factorization.

1642653709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205550.

The product of its (nonzero) digits is 272160, while the sum is 43.

The square root of 1642653709 is about 40529.6645557300. The cubic root of 1642653709 is about 1179.9094321468.

The spelling of 1642653709 in words is "one billion, six hundred forty-two million, six hundred fifty-three thousand, seven hundred nine".