21768708351 has 8 divisors (see below), whose sum is σ = 31257632560. Its totient is φ = 13396128192.

The previous prime is 21768708347. The next prime is 21768708361. The reversal of 21768708351 is 15380786712.

It is a happy number.

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

It is not a de Polignac number, because 21768708351 - 2² = 21768708347 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 21768708351.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21768708361) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 279085966 + ... + 279086043.

It is an arithmetic number, because the mean of its divisors is an integer number (3907204070).

Almost surely, 2^21768708351 is an apocalyptic number.

21768708351 is a deficient number, since it is larger than the sum of its proper divisors (9488924209).

21768708351 is a wasteful number, since it uses less digits than its factorization.

21768708351 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 558172025.

The product of its (nonzero) digits is 564480, while the sum is 48.

The spelling of 21768708351 in words is "twenty-one billion, seven hundred sixty-eight million, seven hundred eight thousand, three hundred fifty-one".