21449999947 has 8 divisors (see below), whose sum is σ = 21693213360. Its totient is φ = 21208157280.

The previous prime is 21449999941. The next prime is 21450000001. The reversal of 21449999947 is 74999994412.

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

It is a cyclic number.

It is not a de Polignac number, because 21449999947 - 2⁷ = 21449999819 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21449999941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 311197 + ... + 373822.

It is an arithmetic number, because the mean of its divisors is an integer number (2711651670).

Almost surely, 2^21449999947 is an apocalyptic number.

21449999947 is a deficient number, since it is larger than the sum of its proper divisors (243213413).

21449999947 is a wasteful number, since it uses less digits than its factorization.

21449999947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 685373.

The product of its digits is 52907904, while the sum is 67.

The spelling of 21449999947 in words is "twenty-one billion, four hundred forty-nine million, nine hundred ninety-nine thousand, nine hundred forty-seven".