21313666351 has 4 divisors (see below), whose sum is σ = 21323900632. Its totient is φ = 21303432072.

The previous prime is 21313666327. The next prime is 21313666373. The reversal of 21313666351 is 15366631312.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21313666351 - 2⁷ = 21313666223 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21313666351.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21313616351) 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, 5114016 + ... + 5118181.

It is an arithmetic number, because the mean of its divisors is an integer number (5330975158).

Almost surely, 2^21313666351 is an apocalyptic number.

21313666351 is a deficient number, since it is larger than the sum of its proper divisors (10234281).

21313666351 is a wasteful number, since it uses less digits than its factorization.

21313666351 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10234280.

The product of its digits is 58320, while the sum is 37.

The spelling of 21313666351 in words is "twenty-one billion, three hundred thirteen million, six hundred sixty-six thousand, three hundred fifty-one".