21159338906 has 16 divisors (see below), whose sum is σ = 31975314624. Its totient is φ = 10501192704.

The previous prime is 21159338903. The next prime is 21159338929. The reversal of 21159338906 is 60983395112.

It is not an unprimeable number, because it can be changed into a prime (21159338903) 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, 72731 + ... + 218193.

It is an arithmetic number, because the mean of its divisors is an integer number (1998457164).

Almost surely, 2^21159338906 is an apocalyptic number.

It is a pronic number, being equal to 145462×145463.

21159338906 is a deficient number, since it is larger than the sum of its proper divisors (10815975718).

21159338906 is a wasteful number, since it uses less digits than its factorization.

21159338906 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146005.

The product of its (nonzero) digits is 349920, while the sum is 47.

The spelling of 21159338906 in words is "twenty-one billion, one hundred fifty-nine million, three hundred thirty-eight thousand, nine hundred six".