921638099 has 2 divisors, whose sum is σ = 921638100. Its totient is φ = 921638098.

The previous prime is 921638089. The next prime is 921638117. The reversal of 921638099 is 990836129.

It is a weak prime.

It is an emirp because it is prime and its reverse (990836129) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 921638099 - 2¹⁶ = 921572563 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (921638089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 460819049 + 460819050.

It is an arithmetic number, because the mean of its divisors is an integer number (460819050).

Almost surely, 2^921638099 is an apocalyptic number.

921638099 is a deficient number, since it is larger than the sum of its proper divisors (1).

921638099 is an equidigital number, since it uses as much as digits as its factorization.

921638099 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 209952, while the sum is 47.

The square root of 921638099 is about 30358.4930291344. The cubic root of 921638099 is about 973.1657291656.

The spelling of 921638099 in words is "nine hundred twenty-one million, six hundred thirty-eight thousand, ninety-nine".