21209279046 has 24 divisors (see below), whose sum is σ = 43596007560. Its totient is φ = 6878682432.

The previous prime is 21209278957. The next prime is 21209279059. The reversal of 21209279046 is 64097290212.

It is a junction number, because it is equal to n+sod(n) for n = 21209278989 and 21209279007.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 1282831 + ... + 1299258.

It is an arithmetic number, because the mean of its divisors is an integer number (1816500315).

Almost surely, 2^21209279046 is an apocalyptic number.

21209279046 is an abundant number, since it is smaller than the sum of its proper divisors (22386728514).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21209279046 is a wasteful number, since it uses less digits than its factorization.

21209279046 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2582168 (or 2582131 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 42.

The spelling of 21209279046 in words is "twenty-one billion, two hundred nine million, two hundred seventy-nine thousand, forty-six".