9997443981 has 48 divisors (see below), whose sum is σ = 17288976000. Its totient is φ = 5707326744.

The previous prime is 9997443979. The next prime is 9997444043. The reversal of 9997443981 is 1893447999.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It is not a de Polignac number, because 9997443981 - 2¹ = 9997443979 is a prime.

It is a super-2 number, since 2×9997443981² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9997443941) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 9621660 + ... + 9622698.

It is an arithmetic number, because the mean of its divisors is an integer number (360187000).

Almost surely, 2^9997443981 is an apocalyptic number.

It is an amenable number.

9997443981 is a deficient number, since it is larger than the sum of its proper divisors (7291532019).

9997443981 is an frugal number, since it uses more digits than its factorization.

9997443981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2108 (or 1049 counting only the distinct ones).

The product of its digits is 17635968, while the sum is 63.

The square root of 9997443981 is about 99987.2190882415. The cubic root of 9997443981 is about 2154.2511151902.

The spelling of 9997443981 in words is "nine billion, nine hundred ninety-seven million, four hundred forty-three thousand, nine hundred eighty-one".