99995981 has 4 divisors (see below), whose sum is σ = 100143072. Its totient is φ = 99848892.

The previous prime is 99995957. The next prime is 99995983. The reversal of 99995981 is 18959999.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99995981 is a prime.

It is a super-2 number, since 2×99995981² = 19998392432304722, which contains 22 as substring.

It is a Duffinian number.

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 99995981.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99995983) 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, 72521 + ... + 73886.

It is an arithmetic number, because the mean of its divisors is an integer number (25035768).

Almost surely, 2^99995981 is an apocalyptic number.

It is an amenable number.

99995981 is a deficient number, since it is larger than the sum of its proper divisors (147091).

99995981 is a wasteful number, since it uses less digits than its factorization.

99995981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147090.

The product of its digits is 2361960, while the sum is 59.

The square root of 99995981 is about 9999.7990479809. The cubic root of 99995981 is about 464.1526650961.

The spelling of 99995981 in words is "ninety-nine million, nine hundred ninety-five thousand, nine hundred eighty-one".