99806421 has 32 divisors (see below), whose sum is σ = 158280192. Its totient is φ = 55143360.

The previous prime is 99806417. The next prime is 99806437. The reversal of 99806421 is 12460899.

It is not a de Polignac number, because 99806421 - 2² = 99806417 is a prime.

It is a super-2 number, since 2×99806421² = 19922643345658482, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a self number, because there is not a number n which added to its sum of digits gives 99806421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99806401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 34206 + ... + 37008.

It is an arithmetic number, because the mean of its divisors is an integer number (4946256).

Almost surely, 2^99806421 is an apocalyptic number.

It is an amenable number.

99806421 is a deficient number, since it is larger than the sum of its proper divisors (58473771).

99806421 is a wasteful number, since it uses less digits than its factorization.

99806421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2913.

The product of its (nonzero) digits is 31104, while the sum is 39.

The square root of 99806421 is about 9990.3163613571. The cubic root of 99806421 is about 463.8591851855.

The spelling of 99806421 in words is "ninety-nine million, eight hundred six thousand, four hundred twenty-one".