21273685641 has 48 divisors (see below), whose sum is σ = 36055062400. Its totient is φ = 12321351936.

The previous prime is 21273685633. The next prime is 21273685661. The reversal of 21273685641 is 14658637212.

21273685641 is a `hidden beast` number, since 2 + 1 + 27 + 3 + 68 + 564 + 1 = 666.

It is not a de Polignac number, because 21273685641 - 2³ = 21273685633 is a prime.

It is a super-3 number, since 3×21273685641³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21273685661) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3421 + ... + 206298.

Almost surely, 2^21273685641 is an apocalyptic number.

It is an amenable number.

21273685641 is a deficient number, since it is larger than the sum of its proper divisors (14781376759).

21273685641 is a wasteful number, since it uses less digits than its factorization.

21273685641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209775 (or 209752 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The spelling of 21273685641 in words is "twenty-one billion, two hundred seventy-three million, six hundred eighty-five thousand, six hundred forty-one".