21991089210 has 64 divisors (see below), whose sum is σ = 53779904640. Its totient is φ = 5754045440.

The previous prime is 21991089191. The next prime is 21991089227. The reversal of 21991089210 is 1298019912.

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 31 ways as a sum of consecutive naturals, for example, 318334 + ... + 381206.

It is an arithmetic number, because the mean of its divisors is an integer number (840311010).

Almost surely, 2^21991089210 is an apocalyptic number.

21991089210 is an abundant number, since it is smaller than the sum of its proper divisors (31788815430).

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

21991089210 is a wasteful number, since it uses less digits than its factorization.

21991089210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63103.

The product of its (nonzero) digits is 23328, while the sum is 42.

The spelling of 21991089210 in words is "twenty-one billion, nine hundred ninety-one million, eighty-nine thousand, two hundred ten".