16442667617221 has 2 divisors, whose sum is σ = 16442667617222. Its totient is φ = 16442667617220.

The previous prime is 16442667617147. The next prime is 16442667617263. The reversal of 16442667617221 is 12271676624461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16422869720196 + 19797897025 = 4052514^2 + 140705^2 .

It is a cyclic number.

It is not a de Polignac number, because 16442667617221 - 2⁷ = 16442667617093 is a prime.

It is a super-3 number, since 3×16442667617221³ (a number of 41 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16442667617021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8221333808610 + 8221333808611.

It is an arithmetic number, because the mean of its divisors is an integer number (8221333808611).

Almost surely, 2^{16442667617221} is an apocalyptic number.

It is an amenable number.

16442667617221 is a deficient number, since it is larger than the sum of its proper divisors (1).

16442667617221 is an equidigital number, since it uses as much as digits as its factorization.

16442667617221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8128512, while the sum is 55.

The spelling of 16442667617221 in words is "sixteen trillion, four hundred forty-two billion, six hundred sixty-seven million, six hundred seventeen thousand, two hundred twenty-one".