16989259970821 has 2 divisors, whose sum is σ = 16989259970822. Its totient is φ = 16989259970820.

The previous prime is 16989259970807. The next prime is 16989259970849. The reversal of 16989259970821 is 12807995298961.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16979665768321 + 9594202500 = 4120639^2 + 97950^2 .

It is a cyclic number.

It is not a de Polignac number, because 16989259970821 - 2¹⁷ = 16989259839749 is a prime.

It is a super-2 number, since 2×16989259970821² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16989259973821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8494629985410 + 8494629985411.

It is an arithmetic number, because the mean of its divisors is an integer number (8494629985411).

Almost surely, 2^{16989259970821} is an apocalyptic number.

It is an amenable number.

16989259970821 is a deficient number, since it is larger than the sum of its proper divisors (1).

16989259970821 is an equidigital number, since it uses as much as digits as its factorization.

16989259970821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 352719360, while the sum is 76.

The spelling of 16989259970821 in words is "sixteen trillion, nine hundred eighty-nine billion, two hundred fifty-nine million, nine hundred seventy thousand, eight hundred twenty-one".