67287712921 has 24 divisors (see below), whose sum is σ = 80956028552. Its totient is φ = 55539475200.

The previous prime is 67287712907. The next prime is 67287712967. The reversal of 67287712921 is 12921778276.

It can be written as a sum of positive squares in 4 ways, for example, as 12777137296 + 54510575625 = 113036^2 + 233475^2 .

It is not a de Polignac number, because 67287712921 - 2¹⁷ = 67287581849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (67287712321) 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 23 ways as a sum of consecutive naturals, for example, 254676 + ... + 446581.

Almost surely, 2^67287712921 is an apocalyptic number.

67287712921 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

It is an amenable number.

67287712921 is a deficient number, since it is larger than the sum of its proper divisors (13668315631).

67287712921 is a wasteful number, since it uses less digits than its factorization.

67287712921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 701353 (or 701342 counting only the distinct ones).

The product of its digits is 1185408, while the sum is 52.

The spelling of 67287712921 in words is "sixty-seven billion, two hundred eighty-seven million, seven hundred twelve thousand, nine hundred twenty-one".