16551765004381 has 2 divisors, whose sum is σ = 16551765004382. Its totient is φ = 16551765004380.

The previous prime is 16551765004361. The next prime is 16551765004409. The reversal of 16551765004381 is 18340056715561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16378451820900 + 173313183481 = 4047030^2 + 416309^2 .

It is a cyclic number.

It is not a de Polignac number, because 16551765004381 - 2⁴³ = 7755671982173 is a prime.

It is a super-2 number, since 2×16551765004381² (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 (16551765004331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8275882502190 + 8275882502191.

It is an arithmetic number, because the mean of its divisors is an integer number (8275882502191).

Almost surely, 2^{16551765004381} is an apocalyptic number.

It is an amenable number.

16551765004381 is a deficient number, since it is larger than the sum of its proper divisors (1).

16551765004381 is an equidigital number, since it uses as much as digits as its factorization.

16551765004381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3024000, while the sum is 52.

The spelling of 16551765004381 in words is "sixteen trillion, five hundred fifty-one billion, seven hundred sixty-five million, four thousand, three hundred eighty-one".