67721271921 has 12 divisors (see below), whose sum is σ = 102072642048. Its totient is φ = 43184579064.

The previous prime is 67721271907. The next prime is 67721271923. The reversal of 67721271921 is 12917212776.

It is not a de Polignac number, because 67721271921 - 2⁵ = 67721271889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (67721271923) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 163577745 + ... + 163578158.

It is an arithmetic number, because the mean of its divisors is an integer number (8506053504).

Almost surely, 2^67721271921 is an apocalyptic number.

It is an amenable number.

67721271921 is a deficient number, since it is larger than the sum of its proper divisors (34351370127).

67721271921 is a wasteful number, since it uses less digits than its factorization.

67721271921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 327155932 (or 327155929 counting only the distinct ones).

The product of its digits is 148176, while the sum is 45.

The spelling of 67721271921 in words is "sixty-seven billion, seven hundred twenty-one million, two hundred seventy-one thousand, nine hundred twenty-one".