21981205010 has 8 divisors (see below), whose sum is σ = 39566169036. Its totient is φ = 8792482000.

The previous prime is 21981205009. The next prime is 21981205031. The reversal of 21981205010 is 1050218912.

It can be written as a sum of positive squares in 2 ways, for example, as 21978952009 + 2253001 = 148253^2 + 1501^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1099060241 + ... + 1099060260.

Almost surely, 2^21981205010 is an apocalyptic number.

21981205010 is a deficient number, since it is larger than the sum of its proper divisors (17584964026).

21981205010 is a wasteful number, since it uses less digits than its factorization.

21981205010 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2198120508.

The product of its (nonzero) digits is 1440, while the sum is 29.

The spelling of 21981205010 in words is "twenty-one billion, nine hundred eighty-one million, two hundred five thousand, ten".