9881397353961 has 27 divisors (see below), whose sum is σ = 16603547290551. Its totient is φ = 5646475052064.

The previous prime is 9881397353921. The next prime is 9881397353963. The reversal of 9881397353961 is 1693537931889.

The square root of 9881397353961 is 3143469.

It is a perfect power (a square), and thus also a powerful number.

9881397353961 is a `hidden beast` number, since 9 + 8 + 8 + 13 + 9 + 73 + 539 + 6 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 22299747561 + 9859097606400 = 149331^2 + 3139920^2 .

It is not a de Polignac number, because 9881397353961 - 2¹¹ = 9881397351913 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 9881397353961.

It is not an unprimeable number, because it can be changed into a prime (9881397353963) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 65938005 + ... + 66087693.

Almost surely, 2^{9881397353961} is an apocalyptic number.

9881397353961 is the 3143469-th square number.

9881397353961 is the 1571735-th centered octagonal number.

It is an amenable number.

9881397353961 is a deficient number, since it is larger than the sum of its proper divisors (6722149936590).

9881397353961 is an frugal number, since it uses more digits than its factorization.

9881397353961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 299398 (or 149699 counting only the distinct ones).

The product of its digits is 264539520, while the sum is 72.

The spelling of 9881397353961 in words is "nine trillion, eight hundred eighty-one billion, three hundred ninety-seven million, three hundred fifty-three thousand, nine hundred sixty-one".