667214537521 has 16 divisors (see below), whose sum is σ = 765369402880. Its totient is φ = 569772403200.

The previous prime is 667214537449. The next prime is 667214537531. The reversal of 667214537521 is 125735412766.

667214537521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 667214537521 - 2⁹ = 667214537009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (667214537531) 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, 2463421 + ... + 2720821.

It is an arithmetic number, because the mean of its divisors is an integer number (47835587680).

Almost surely, 2^667214537521 is an apocalyptic number.

It is an amenable number.

667214537521 is a deficient number, since it is larger than the sum of its proper divisors (98154865359).

667214537521 is a wasteful number, since it uses less digits than its factorization.

667214537521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 258784.

The product of its digits is 2116800, while the sum is 49.

The spelling of 667214537521 in words is "six hundred sixty-seven billion, two hundred fourteen million, five hundred thirty-seven thousand, five hundred twenty-one".