17621720849 has 8 divisors (see below), whose sum is σ = 17645688000. Its totient is φ = 17597772976.

The previous prime is 17621720813. The next prime is 17621720881. The reversal of 17621720849 is 94802712671.

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 17621720849 - 2¹² = 17621716753 is a prime.

It is a super-4 number, since 4×17621720849⁴ (a number of 42 digits) contains 4444 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (17621720749) 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, 2810492 + ... + 2816754.

It is an arithmetic number, because the mean of its divisors is an integer number (2205711000).

Almost surely, 2^17621720849 is an apocalyptic number.

It is an amenable number.

17621720849 is a deficient number, since it is larger than the sum of its proper divisors (23967151).

17621720849 is a wasteful number, since it uses less digits than its factorization.

17621720849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9639.

The product of its (nonzero) digits is 338688, while the sum is 47.

The spelling of 17621720849 in words is "seventeen billion, six hundred twenty-one million, seven hundred twenty thousand, eight hundred forty-nine".