21177345643672 has 16 divisors (see below), whose sum is σ = 39767777299800. Its totient is φ = 10572605030400.

The previous prime is 21177345643621. The next prime is 21177345643687. The reversal of 21177345643672 is 27634654377112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2008468329 + ... + 2008478872.

Almost surely, 2^{21177345643672} is an apocalyptic number.

It is an amenable number.

21177345643672 is a deficient number, since it is larger than the sum of its proper divisors (18590431656128).

21177345643672 is a wasteful number, since it uses less digits than its factorization.

21177345643672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4016947866 (or 4016947862 counting only the distinct ones).

The product of its digits is 35562240, while the sum is 58.

The spelling of 21177345643672 in words is "twenty-one trillion, one hundred seventy-seven billion, three hundred forty-five million, six hundred forty-three thousand, six hundred seventy-two".