16651532039381 has 2 divisors, whose sum is σ = 16651532039382. Its totient is φ = 16651532039380.

The previous prime is 16651532039369. The next prime is 16651532039399. The reversal of 16651532039381 is 18393023515661.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16565307002500 + 86225036881 = 4070050^2 + 293641^2 .

It is an emirp because it is prime and its reverse (18393023515661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16651532039381 - 2²⁶ = 16651464930517 is a prime.

It is a super-2 number, since 2×16651532039381² (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 (16651532039281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8325766019690 + 8325766019691.

It is an arithmetic number, because the mean of its divisors is an integer number (8325766019691).

Almost surely, 2^{16651532039381} is an apocalyptic number.

It is an amenable number.

16651532039381 is a deficient number, since it is larger than the sum of its proper divisors (1).

16651532039381 is an equidigital number, since it uses as much as digits as its factorization.

16651532039381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3499200, while the sum is 53.

The spelling of 16651532039381 in words is "sixteen trillion, six hundred fifty-one billion, five hundred thirty-two million, thirty-nine thousand, three hundred eighty-one".