99281077921 has 9 divisors (see below), whose sum is σ = 99639360849. Its totient is φ = 98924082084.

The previous prime is 99281077913. The next prime is 99281077939. The reversal of 99281077921 is 12977018299.

The square root of 99281077921 is 315089.

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

It is not a de Polignac number, because 99281077921 - 2³ = 99281077913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99281077981) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 153448020 + ... + 153448666.

Almost surely, 2^99281077921 is an apocalyptic number.

99281077921 is the 315089-th square number.

99281077921 is the 157545-th centered octagonal number.

It is an amenable number.

99281077921 is a deficient number, since it is larger than the sum of its proper divisors (358282928).

99281077921 is an frugal number, since it uses more digits than its factorization.

99281077921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2268 (or 1134 counting only the distinct ones).

The product of its (nonzero) digits is 1143072, while the sum is 55.

It can be divided in two parts, 9928 and 1077921, that added together give a square (1087849 = 1043²).

The spelling of 99281077921 in words is "ninety-nine billion, two hundred eighty-one million, seventy-seven thousand, nine hundred twenty-one".