21729063028 has 12 divisors (see below), whose sum is σ = 38649235492. Its totient is φ = 10686424320.

The previous prime is 21729063019. The next prime is 21729063053. The reversal of 21729063028 is 82036092712.

It can be written as a sum of positive squares in 2 ways, for example, as 10888505104 + 10840557924 = 104348^2 + 104118^2 .

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, 44526525 + ... + 44527012.

Almost surely, 2^21729063028 is an apocalyptic number.

It is an amenable number.

21729063028 is a deficient number, since it is larger than the sum of its proper divisors (16920172464).

21729063028 is a wasteful number, since it uses less digits than its factorization.

21729063028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89053602 (or 89053600 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 40.

The spelling of 21729063028 in words is "twenty-one billion, seven hundred twenty-nine million, sixty-three thousand, twenty-eight".