21007872717473 has 2 divisors, whose sum is σ = 21007872717474. Its totient is φ = 21007872717472.

The previous prime is 21007872717463. The next prime is 21007872717497. The reversal of 21007872717473 is 37471727870012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14787278048929 + 6220594668544 = 3845423^2 + 2494112^2 .

It is a cyclic number.

It is not a de Polignac number, because 21007872717473 - 2⁴ = 21007872717457 is a prime.

It is a super-2 number, since 2×21007872717473² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21007872717463) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10503936358736 + 10503936358737.

It is an arithmetic number, because the mean of its divisors is an integer number (10503936358737).

Almost surely, 2^{21007872717473} is an apocalyptic number.

It is an amenable number.

21007872717473 is a deficient number, since it is larger than the sum of its proper divisors (1).

21007872717473 is an equidigital number, since it uses as much as digits as its factorization.

21007872717473 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6453888, while the sum is 56.

The spelling of 21007872717473 in words is "twenty-one trillion, seven billion, eight hundred seventy-two million, seven hundred seventeen thousand, four hundred seventy-three".