8401989121 has 4 divisors (see below), whose sum is σ = 8479071700. Its totient is φ = 8324906544.

The previous prime is 8401989109. The next prime is 8401989131. The reversal of 8401989121 is 1219891048.

It is a happy number.

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 2053086721 + 6348902400 = 45311^2 + 79680^2 .

It is a cyclic number.

It is not a de Polignac number, because 8401989121 - 2¹⁹ = 8401464833 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8401989131) 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, 38541126 + ... + 38541343.

It is an arithmetic number, because the mean of its divisors is an integer number (2119767925).

Almost surely, 2^8401989121 is an apocalyptic number.

It is an amenable number.

8401989121 is a deficient number, since it is larger than the sum of its proper divisors (77082579).

8401989121 is a wasteful number, since it uses less digits than its factorization.

8401989121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77082578.

The product of its (nonzero) digits is 41472, while the sum is 43.

The square root of 8401989121 is about 91662.3648014822. The cubic root of 8401989121 is about 2032.9531561516.

The spelling of 8401989121 in words is "eight billion, four hundred one million, nine hundred eighty-nine thousand, one hundred twenty-one".