21121368909 has 8 divisors (see below), whose sum is σ = 28183848960. Its totient is φ = 14069900736.

The previous prime is 21121368907. The next prime is 21121368953. The reversal of 21121368909 is 90986312112.

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

It is not a de Polignac number, because 21121368909 - 2¹ = 21121368907 is a prime.

It is a super-2 number, since 2×21121368909² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121368907) 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 7 ways as a sum of consecutive naturals, for example, 2748492 + ... + 2756165.

It is an arithmetic number, because the mean of its divisors is an integer number (3522981120).

Almost surely, 2^21121368909 is an apocalyptic number.

It is an amenable number.

21121368909 is a deficient number, since it is larger than the sum of its proper divisors (7062480051).

21121368909 is a wasteful number, since it uses less digits than its factorization.

21121368909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5505939.

The product of its (nonzero) digits is 46656, while the sum is 42.

The spelling of 21121368909 in words is "twenty-one billion, one hundred twenty-one million, three hundred sixty-eight thousand, nine hundred nine".