21003273729 has 32 divisors (see below), whose sum is σ = 32903162880. Its totient is φ = 13219977600.

The previous prime is 21003273673. The next prime is 21003273757. The reversal of 21003273729 is 92737230012.

It is not a de Polignac number, because 21003273729 - 2⁷ = 21003273601 is a prime.

It is a super-2 number, since 2×21003273729² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21003273693 and 21003273702.

It is not an unprimeable number, because it can be changed into a prime (21003273799) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 271702 + ... + 340335.

It is an arithmetic number, because the mean of its divisors is an integer number (1028223840).

Almost surely, 2^21003273729 is an apocalyptic number.

It is an amenable number.

21003273729 is a deficient number, since it is larger than the sum of its proper divisors (11899889151).

21003273729 is a wasteful number, since it uses less digits than its factorization.

21003273729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 612118 (or 612112 counting only the distinct ones).

The product of its (nonzero) digits is 31752, while the sum is 36.

The spelling of 21003273729 in words is "twenty-one billion, three million, two hundred seventy-three thousand, seven hundred twenty-nine".