673542939457521 has 64 divisors (see below), whose sum is σ = 1157436774144000. Its totient is φ = 379155022003008.

The previous prime is 673542939457499. The next prime is 673542939457541. The reversal of 673542939457521 is 125754939245376.

673542939457521 is a `hidden beast` number, since 6 + 7 + 3 + 5 + 4 + 2 + 9 + 3 + 94 + 5 + 7 + 521 = 666.

It is not a de Polignac number, because 673542939457521 - 2⁹ = 673542939457009 is a prime.

It is a hoax number, since the sum of its digits (72) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 673542939457521.

It is not an unprimeable number, because it can be changed into a prime (673542939457541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 56038671 + ... + 66988196.

It is an arithmetic number, because the mean of its divisors is an integer number (18084949596000).

Almost surely, 2^{673542939457521} is an apocalyptic number.

It is an amenable number.

673542939457521 is a deficient number, since it is larger than the sum of its proper divisors (483893834686479).

673542939457521 is a wasteful number, since it uses less digits than its factorization.

673542939457521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123027315 (or 123027309 counting only the distinct ones).

The product of its digits is 1714608000, while the sum is 72.

The spelling of 673542939457521 in words is "six hundred seventy-three trillion, five hundred forty-two billion, nine hundred thirty-nine million, four hundred fifty-seven thousand, five hundred twenty-one".