21210099 has 8 divisors (see below), whose sum is σ = 29768640. Its totient is φ = 13395816.

The previous prime is 21210097. The next prime is 21210103. The reversal of 21210099 is 99001212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21210099 - 2¹ = 21210097 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21210097) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 185997 + ... + 186110.

It is an arithmetic number, because the mean of its divisors is an integer number (3721080).

Almost surely, 2^21210099 is an apocalyptic number.

21210099 is a deficient number, since it is larger than the sum of its proper divisors (8558541).

21210099 is a wasteful number, since it uses less digits than its factorization.

21210099 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 372129.

The product of its (nonzero) digits is 324, while the sum is 24.

The square root of 21210099 is about 4605.4423240336. The cubic root of 21210099 is about 276.8094411547.

The spelling of 21210099 in words is "twenty-one million, two hundred ten thousand, ninety-nine".