1664021013 has 16 divisors (see below), whose sum is σ = 2387722176. Its totient is φ = 1026973440.

The previous prime is 1664020991. The next prime is 1664021033. The reversal of 1664021013 is 3101204661.

1664021013 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 1664021013 - 2⁶ = 1664020949 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1664021033) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 264331 + ... + 270552.

It is an arithmetic number, because the mean of its divisors is an integer number (149232636).

Almost surely, 2^1664021013 is an apocalyptic number.

It is an amenable number.

1664021013 is a deficient number, since it is larger than the sum of its proper divisors (723701163).

1664021013 is a wasteful number, since it uses less digits than its factorization.

1664021013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 534964.

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 1664021013 is about 40792.4136697009. The cubic root of 1664021013 is about 1185.0034153972.

Adding to 1664021013 its reverse (3101204661), we get a palindrome (4765225674).

The spelling of 1664021013 in words is "one billion, six hundred sixty-four million, twenty-one thousand, thirteen".