17221001661 has 12 divisors (see below), whose sum is σ = 24888707740. Its totient is φ = 11474239680.

The previous prime is 17221001659. The next prime is 17221001663. The reversal of 17221001661 is 16610012271.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (17221001659) and next prime (17221001663).

It can be written as a sum of positive squares in 2 ways, for example, as 15121620900 + 2099380761 = 122970^2 + 45819^2 .

It is not a de Polignac number, because 17221001661 - 2¹ = 17221001659 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 (17221001663) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 518680 + ... + 550881.

Almost surely, 2^17221001661 is an apocalyptic number.

It is an amenable number.

17221001661 is a deficient number, since it is larger than the sum of its proper divisors (7667706079).

17221001661 is a wasteful number, since it uses less digits than its factorization.

17221001661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1071356 (or 1071353 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 27.

The spelling of 17221001661 in words is "seventeen billion, two hundred twenty-one million, one thousand, six hundred sixty-one".