1645683513 has 4 divisors (see below), whose sum is σ = 2194244688. Its totient is φ = 1097122340.

The previous prime is 1645683509. The next prime is 1645683541. The reversal of 1645683513 is 3153865461.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1645683513 - 2² = 1645683509 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1645683563) 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, 274280583 + ... + 274280588.

It is an arithmetic number, because the mean of its divisors is an integer number (548561172).

Almost surely, 2^1645683513 is an apocalyptic number.

It is an amenable number.

1645683513 is a deficient number, since it is larger than the sum of its proper divisors (548561175).

1645683513 is an equidigital number, since it uses as much as digits as its factorization.

1645683513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 548561174.

The product of its digits is 259200, while the sum is 42.

The square root of 1645683513 is about 40567.0249463773. The cubic root of 1645683513 is about 1180.6344173003.

The spelling of 1645683513 in words is "one billion, six hundred forty-five million, six hundred eighty-three thousand, five hundred thirteen".