989945442475021 has 4 divisors (see below), whose sum is σ = 990173698288092. Its totient is φ = 989717186661952.

The previous prime is 989945442474997. The next prime is 989945442475069. The reversal of 989945442475021 is 120574244549989.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 234820378822500 + 755125063652521 = 15323850^2 + 27479539^2 .

It is a cyclic number.

It is not a de Polignac number, because 989945442475021 - 2¹³ = 989945442466829 is a prime.

It is a super-2 number, since 2×989945442475021² (a number of 31 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (989945442475421) 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, 114127900030 + ... + 114127908703.

It is an arithmetic number, because the mean of its divisors is an integer number (247543424572023).

Almost surely, 2^{989945442475021} is an apocalyptic number.

It is an amenable number.

989945442475021 is a deficient number, since it is larger than the sum of its proper divisors (228255813071).

989945442475021 is a wasteful number, since it uses less digits than its factorization.

989945442475021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 228255813070.

The product of its (nonzero) digits is 1045094400, while the sum is 73.

The spelling of 989945442475021 in words is "nine hundred eighty-nine trillion, nine hundred forty-five billion, four hundred forty-two million, four hundred seventy-five thousand, twenty-one".