1667521013 has 4 divisors (see below), whose sum is σ = 1668556428. Its totient is φ = 1666485600.

The previous prime is 1667521001. The next prime is 1667521027. The reversal of 1667521013 is 3101257661.

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 1114424689 + 553096324 = 33383^2 + 23518^2 .

It is a cyclic number.

It is not a de Polignac number, because 1667521013 - 2²⁸ = 1399085557 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1667521213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 515288 + ... + 518513.

It is an arithmetic number, because the mean of its divisors is an integer number (417139107).

Almost surely, 2^1667521013 is an apocalyptic number.

It is an amenable number.

1667521013 is a deficient number, since it is larger than the sum of its proper divisors (1035415).

1667521013 is a wasteful number, since it uses less digits than its factorization.

1667521013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1035414.

The product of its (nonzero) digits is 7560, while the sum is 32.

The square root of 1667521013 is about 40835.2912687053. The cubic root of 1667521013 is about 1185.8336548073.

Adding to 1667521013 its reverse (3101257661), we get a palindrome (4768778674).

The spelling of 1667521013 in words is "one billion, six hundred sixty-seven million, five hundred twenty-one thousand, thirteen".