29851891729 has 27 divisors (see below), whose sum is σ = 33345236379. Its totient is φ = 26704413120.

The previous prime is 29851891723. The next prime is 29851891739. The reversal of 29851891729 is 92719815892.

The square root of 29851891729 is 172777.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 526014225 + 29325877504 = 22935^2 + 171248^2 .

It is not a de Polignac number, because 29851891729 - 2²³ = 29843503121 is a prime.

It is a super-2 number, since 2×29851891729² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (29851891723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 214761742 + ... + 214761880.

Almost surely, 2^29851891729 is an apocalyptic number.

29851891729 is the 172777-th square number.

29851891729 is the 86389-th centered octagonal number.

It is an amenable number.

29851891729 is a deficient number, since it is larger than the sum of its proper divisors (3493344650).

29851891729 is an equidigital number, since it uses as much as digits as its factorization.

29851891729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 526 (or 263 counting only the distinct ones).

The product of its digits is 6531840, while the sum is 61.

The spelling of 29851891729 in words is "twenty-nine billion, eight hundred fifty-one million, eight hundred ninety-one thousand, seven hundred twenty-nine".