1645512013 has 2 divisors, whose sum is σ = 1645512014. Its totient is φ = 1645512012.

The previous prime is 1645511993. The next prime is 1645512031. The reversal of 1645512013 is 3102155461.

Together with next prime (1645512031) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1436940649 + 208571364 = 37907^2 + 14442^2 .

It is a cyclic number.

It is not a de Polignac number, because 1645512013 - 2¹⁷ = 1645380941 is a prime.

It is a super-4 number, since 4×1645512013⁴ (a number of 38 digits) contains 4444 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1645512073) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 822756006 + 822756007.

It is an arithmetic number, because the mean of its divisors is an integer number (822756007).

Almost surely, 2^1645512013 is an apocalyptic number.

It is an amenable number.

1645512013 is a deficient number, since it is larger than the sum of its proper divisors (1).

1645512013 is an equidigital number, since it uses as much as digits as its factorization.

1645512013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3600, while the sum is 28.

The square root of 1645512013 is about 40564.9111055355. The cubic root of 1645512013 is about 1180.5934037771.

Adding to 1645512013 its reverse (3102155461), we get a palindrome (4747667474).

The spelling of 1645512013 in words is "one billion, six hundred forty-five million, five hundred twelve thousand, thirteen".