21210669790 has 8 divisors (see below), whose sum is σ = 38179205640. Its totient is φ = 8484267912.

The previous prime is 21210669761. The next prime is 21210669791. The reversal of 21210669790 is 9796601212.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210669791) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1060533480 + ... + 1060533499.

It is an arithmetic number, because the mean of its divisors is an integer number (4772400705).

Almost surely, 2^21210669790 is an apocalyptic number.

21210669790 is a deficient number, since it is larger than the sum of its proper divisors (16968535850).

21210669790 is a wasteful number, since it uses less digits than its factorization.

21210669790 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2121066986.

The product of its (nonzero) digits is 81648, while the sum is 43.

The spelling of 21210669790 in words is "twenty-one billion, two hundred ten million, six hundred sixty-nine thousand, seven hundred ninety".