67566121921 has 4 divisors (see below), whose sum is σ = 67848825600. Its totient is φ = 67283418244.

The previous prime is 67566121919. The next prime is 67566121943. The reversal of 67566121921 is 12912166576.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 67566121921 - 2¹ = 67566121919 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (67566101921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 141351481 + ... + 141351958.

It is an arithmetic number, because the mean of its divisors is an integer number (16962206400).

Almost surely, 2^67566121921 is an apocalyptic number.

It is an amenable number.

67566121921 is a deficient number, since it is larger than the sum of its proper divisors (282703679).

67566121921 is a wasteful number, since it uses less digits than its factorization.

67566121921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 282703678.

The product of its digits is 272160, while the sum is 46.

The spelling of 67566121921 in words is "sixty-seven billion, five hundred sixty-six million, one hundred twenty-one thousand, nine hundred twenty-one".