1916683717221 has 240 divisors, whose sum is σ = 3811495731120. Its totient is φ = 951401687040.

The previous prime is 1916683717147. The next prime is 1916683717229. The reversal of 1916683717221 is 1227173866191.

1916683717221 is a `hidden beast` number, since 191 + 6 + 68 + 371 + 7 + 2 + 21 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 149142716100 + 1767541001121 = 386190^2 + 1329489^2 .

It is not a de Polignac number, because 1916683717221 - 2¹¹ = 1916683715173 is a prime.

It is a super-2 number, since 2×1916683717221² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1916683717229) by changing a digit.

It is a polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 253492281 + ... + 253499841.

It is an arithmetic number, because the mean of its divisors is an integer number (15881232213).

Almost surely, 2^{1916683717221} is an apocalyptic number.

It is an amenable number.

1916683717221 is a deficient number, since it is larger than the sum of its proper divisors (1894812013899).

1916683717221 is an equidigital number, since it uses as much as digits as its factorization.

1916683717221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7651 (or 7601 counting only the distinct ones).

The product of its digits is 1524096, while the sum is 54.

The spelling of 1916683717221 in words is "one trillion, nine hundred sixteen billion, six hundred eighty-three million, seven hundred seventeen thousand, two hundred twenty-one".