99721167 has 32 divisors (see below), whose sum is σ = 173279232. Its totient is φ = 49503744.

The previous prime is 99721163. The next prime is 99721229. The reversal of 99721167 is 76112799.

It is a happy number.

It is not a de Polignac number, because 99721167 - 2² = 99721163 is a prime.

It is a super-2 number, since 2×99721167² = 19888622295683778, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99721163) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6103 + ... + 15384.

It is an arithmetic number, because the mean of its divisors is an integer number (5414976).

Almost surely, 2^99721167 is an apocalyptic number.

99721167 is a deficient number, since it is larger than the sum of its proper divisors (73558065).

99721167 is a wasteful number, since it uses less digits than its factorization.

99721167 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21527.

The product of its digits is 47628, while the sum is 42.

The square root of 99721167 is about 9986.0486179469. The cubic root of 99721167 is about 463.7270723887.

The spelling of 99721167 in words is "ninety-nine million, seven hundred twenty-one thousand, one hundred sixty-seven".