99984781 has 4 divisors (see below), whose sum is σ = 107675932. Its totient is φ = 92293632.

The previous prime is 99984757. The next prime is 99984817. The reversal of 99984781 is 18748999.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18748999 = 383 ⋅48953.

It can be written as a sum of positive squares in 2 ways, for example, as 50282281 + 49702500 = 7091^2 + 7050^2 .

It is a cyclic number.

It is not a de Polignac number, because 99984781 - 2¹³ = 99976589 is a prime.

It is a super-2 number, since 2×99984781² = 19993912863235922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99984751) 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, 3845556 + ... + 3845581.

It is an arithmetic number, because the mean of its divisors is an integer number (26918983).

Almost surely, 2^99984781 is an apocalyptic number.

It is an amenable number.

99984781 is a deficient number, since it is larger than the sum of its proper divisors (7691151).

99984781 is a wasteful number, since it uses less digits than its factorization.

99984781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7691150.

The product of its digits is 1306368, while the sum is 55.

The square root of 99984781 is about 9999.2390210456. The cubic root of 99984781 is about 464.1353353865.

The spelling of 99984781 in words is "ninety-nine million, nine hundred eighty-four thousand, seven hundred eighty-one".