99951 has 4 divisors (see below), whose sum is σ = 133272. Its totient is φ = 66632.

The previous prime is 99929. The next prime is 99961. The reversal of 99951 is 15999.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15999 = 3 ⋅5333.

It is a cyclic number.

It is not a de Polignac number, because 99951 - 2⁷ = 99823 is a prime.

It is a D-number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99901) 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, 16656 + ... + 16661.

It is an arithmetic number, because the mean of its divisors is an integer number (33318).

2⁹⁹⁹⁵¹ is an apocalyptic number.

99951 is a deficient number, since it is larger than the sum of its proper divisors (33321).

99951 is a wasteful number, since it uses less digits than its factorization.

99951 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33320.

The product of its digits is 3645, while the sum is 33.

The square root of 99951 is about 316.1502807211. The cubic root of 99951 is about 46.4083058358.

It can be divided in two parts, 99 and 951, that multiplied together give a palindrome (94149).

The spelling of 99951 in words is "ninety-nine thousand, nine hundred fifty-one".