21111449309 has 12 divisors (see below), whose sum is σ = 22288134240. Its totient is φ = 19993969800.

The previous prime is 21111449299. The next prime is 21111449341. The reversal of 21111449309 is 90394411112.

It is a de Polignac number, because none of the positive numbers 2^k-21111449309 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21111449389) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1443584 + ... + 1458134.

It is an arithmetic number, because the mean of its divisors is an integer number (1857344520).

Almost surely, 2^21111449309 is an apocalyptic number.

It is an amenable number.

21111449309 is a deficient number, since it is larger than the sum of its proper divisors (1176684931).

21111449309 is a wasteful number, since it uses less digits than its factorization.

21111449309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18608 (or 18589 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 35.

The spelling of 21111449309 in words is "twenty-one billion, one hundred eleven million, four hundred forty-nine thousand, three hundred nine".