16217758021 has 4 divisors (see below), whose sum is σ = 16325160544. Its totient is φ = 16110355500.

The previous prime is 16217758019. The next prime is 16217758031. The reversal of 16217758021 is 12085771261.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 16217758021 - 2¹ = 16217758019 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16217758031) 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, 53701035 + ... + 53701336.

It is an arithmetic number, because the mean of its divisors is an integer number (4081290136).

Almost surely, 2^16217758021 is an apocalyptic number.

It is an amenable number.

16217758021 is a deficient number, since it is larger than the sum of its proper divisors (107402523).

16217758021 is a wasteful number, since it uses less digits than its factorization.

16217758021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107402522.

The product of its (nonzero) digits is 47040, while the sum is 40.

The spelling of 16217758021 in words is "sixteen billion, two hundred seventeen million, seven hundred fifty-eight thousand, twenty-one".