989405211021 has 4 divisors (see below), whose sum is σ = 1319206948032. Its totient is φ = 659603474012.

The previous prime is 989405211007. The next prime is 989405211029. The reversal of 989405211021 is 120112504989.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 989405211021 - 2⁶ = 989405210957 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (989405211029) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 164900868501 + ... + 164900868506.

It is an arithmetic number, because the mean of its divisors is an integer number (329801737008).

Almost surely, 2^989405211021 is an apocalyptic number.

It is an amenable number.

989405211021 is a deficient number, since it is larger than the sum of its proper divisors (329801737011).

989405211021 is a wasteful number, since it uses less digits than its factorization.

989405211021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 329801737010.

The product of its (nonzero) digits is 51840, while the sum is 42.

The spelling of 989405211021 in words is "nine hundred eighty-nine billion, four hundred five million, two hundred eleven thousand, twenty-one".