21055909299 has 4 divisors (see below), whose sum is σ = 28074545736. Its totient is φ = 14037272864.

The previous prime is 21055909219. The next prime is 21055909327. The reversal of 21055909299 is 99290955012.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21055909299 - 2¹³ = 21055901107 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21055909219) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3509318214 + ... + 3509318219.

It is an arithmetic number, because the mean of its divisors is an integer number (7018636434).

Almost surely, 2^21055909299 is an apocalyptic number.

21055909299 is a deficient number, since it is larger than the sum of its proper divisors (7018636437).

21055909299 is an equidigital number, since it uses as much as digits as its factorization.

21055909299 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7018636436.

The product of its (nonzero) digits is 656100, while the sum is 51.

The spelling of 21055909299 in words is "twenty-one billion, fifty-five million, nine hundred nine thousand, two hundred ninety-nine".