997641847881 has 48 divisors (see below), whose sum is σ = 1650448450560. Its totient is φ = 568853837280.

The previous prime is 997641847879. The next prime is 997641847907. The reversal of 997641847881 is 188748146799.

997641847881 is a `hidden beast` number, since 9 + 9 + 7 + 64 + 18 + 478 + 81 = 666.

It is not a de Polignac number, because 997641847881 - 2¹ = 997641847879 is a prime.

It is a super-2 number, since 2×997641847881² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (997641847831) 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, 183691236 + ... + 183696666.

It is an arithmetic number, because the mean of its divisors is an integer number (34384342720).

Almost surely, 2^997641847881 is an apocalyptic number.

It is an amenable number.

997641847881 is a deficient number, since it is larger than the sum of its proper divisors (652806602679).

997641847881 is a wasteful number, since it uses less digits than its factorization.

997641847881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11186 (or 11183 counting only the distinct ones).

The product of its digits is 195084288, while the sum is 72.

The spelling of 997641847881 in words is "nine hundred ninety-seven billion, six hundred forty-one million, eight hundred forty-seven thousand, eight hundred eighty-one".