667541453821 has 16 divisors (see below), whose sum is σ = 738314898048. Its totient is φ = 598451846400.

The previous prime is 667541453807. The next prime is 667541453837. The reversal of 667541453821 is 128354145766.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-667541453821 is a prime.

It is a super-2 number, since 2×667541453821² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (667541453881) 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, 5534841 + ... + 5654161.

It is an arithmetic number, because the mean of its divisors is an integer number (46144681128).

Almost surely, 2^667541453821 is an apocalyptic number.

It is an amenable number.

667541453821 is a deficient number, since it is larger than the sum of its proper divisors (70773444227).

667541453821 is a wasteful number, since it uses less digits than its factorization.

667541453821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126372.

The product of its digits is 4838400, while the sum is 52.

The spelling of 667541453821 in words is "six hundred sixty-seven billion, five hundred forty-one million, four hundred fifty-three thousand, eight hundred twenty-one".