9912729821 has 8 divisors (see below), whose sum is σ = 9944098944. Its totient is φ = 9881385120.

The previous prime is 9912729791. The next prime is 9912729833. The reversal of 9912729821 is 1289272199.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 9912729821 - 2²² = 9908535517 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 9912729821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9912729851) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1127081 + ... + 1135841.

It is an arithmetic number, because the mean of its divisors is an integer number (1243012368).

Almost surely, 2^9912729821 is an apocalyptic number.

It is an amenable number.

9912729821 is a deficient number, since it is larger than the sum of its proper divisors (31369123).

9912729821 is a wasteful number, since it uses less digits than its factorization.

9912729821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12211.

The product of its digits is 326592, while the sum is 50.

The square root of 9912729821 is about 99562.6929175783. The cubic root of 9912729821 is about 2148.1491062471.

The spelling of 9912729821 in words is "nine billion, nine hundred twelve million, seven hundred twenty-nine thousand, eight hundred twenty-one".