99921951 has 16 divisors (see below), whose sum is σ = 148230400.
Its totient is φ = 66525624.
The previous prime is 99921947. The next prime is 99921973. The reversal of 99921951 is 15912999.
It is not a de Polignac number, because 99921951 - 22 = 99921947 is a prime.
It is a Duffinian number.
99921951 is a modest number, since divided by 21951 gives 999 as remainder.
It is a junction number, because it is equal to n+sod(n) for n = 99921897 and 99921906.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (99921911) by changing a digit.
It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22800 + ... + 26826.
It is an arithmetic number, because the mean of its divisors is an integer number (9264400).
Almost surely, 299921951 is an apocalyptic number.
99921951 is a deficient number, since it is larger than the sum of its proper divisors (48308449).
99921951 is a wasteful number, since it uses less digits than its factorization.
99921951 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 4955 (or 4949 counting only the distinct ones).
The product of its digits is 65610, while the sum is 45.
The square root of 99921951 is about 9996.0967882469.
The cubic root of 99921951 is about 464.0380948088.
The spelling of 99921951 in words is "ninety-nine million, nine hundred twenty-one thousand, nine hundred fifty-one".