1646320513 has 4 divisors (see below), whose sum is σ = 1690815700. Its totient is φ = 1601825328.

The previous prime is 1646320471. The next prime is 1646320547. The reversal of 1646320513 is 3150236461.

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 1511110129 + 135210384 = 38873^2 + 11628^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1646320513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1646320553) 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, 22247538 + ... + 22247611.

It is an arithmetic number, because the mean of its divisors is an integer number (422703925).

Almost surely, 2^1646320513 is an apocalyptic number.

It is an amenable number.

1646320513 is a deficient number, since it is larger than the sum of its proper divisors (44495187).

1646320513 is an equidigital number, since it uses as much as digits as its factorization.

1646320513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44495186.

The product of its (nonzero) digits is 12960, while the sum is 31.

The square root of 1646320513 is about 40574.8753910594. The cubic root of 1646320513 is about 1180.7867283014.

Adding to 1646320513 its reverse (3150236461), we get a palindrome (4796556974).

The spelling of 1646320513 in words is "one billion, six hundred forty-six million, three hundred twenty thousand, five hundred thirteen".