21716051657 has 8 divisors (see below), whose sum is σ = 22662366720. Its totient is φ = 20769914880.

The previous prime is 21716051641. The next prime is 21716051663. The reversal of 21716051657 is 75615061712.

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

It is a cyclic number.

It is not a de Polignac number, because 21716051657 - 2⁴ = 21716051641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21716051557) 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, 244232 + ... + 321062.

It is an arithmetic number, because the mean of its divisors is an integer number (2832795840).

Almost surely, 2^21716051657 is an apocalyptic number.

It is an amenable number.

21716051657 is a deficient number, since it is larger than the sum of its proper divisors (946315063).

21716051657 is a wasteful number, since it uses less digits than its factorization.

21716051657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89143.

The product of its (nonzero) digits is 88200, while the sum is 41.

The spelling of 21716051657 in words is "twenty-one billion, seven hundred sixteen million, fifty-one thousand, six hundred fifty-seven".