667557551643 has 8 divisors (see below), whose sum is σ = 891785138256. Its totient is φ = 444184166400.

The previous prime is 667557551597. The next prime is 667557551669. The reversal of 667557551643 is 346155755766.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 667557551643 - 2⁸ = 667557551387 is a prime.

It is a super-2 number, since 2×667557551643² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (667557551693) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 213548518 + ... + 213551643.

It is an arithmetic number, because the mean of its divisors is an integer number (111473142282).

Almost surely, 2^667557551643 is an apocalyptic number.

667557551643 is a deficient number, since it is larger than the sum of its proper divisors (224227586613).

667557551643 is a wasteful number, since it uses less digits than its factorization.

667557551643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 427100685.

The product of its digits is 79380000, while the sum is 60.

The spelling of 667557551643 in words is "six hundred sixty-seven billion, five hundred fifty-seven million, five hundred fifty-one thousand, six hundred forty-three".