16363987661997 has 10 divisors (see below), whose sum is σ = 24444969223598. Its totient is φ = 10909325107944.

The previous prime is 16363987661969. The next prime is 16363987661999. The reversal of 16363987661997 is 79916678936361.

16363987661997 is a `hidden beast` number, since 1 + 6 + 36 + 398 + 7 + 6 + 6 + 199 + 7 = 666.

It can be written as a sum of positive squares in only one way, i.e., 13744659049641 + 2619328612356 = 3707379^2 + 1618434^2 .

It is not a de Polignac number, because 16363987661997 - 2⁸ = 16363987661741 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (81), and also a Moran number because the ratio is a prime number: 202024539037 = 16363987661997 / (1 + 6 + 3 + 6 + 3 + 9 + 8 + 7 + 6 + 6 + 1 + 9 + 9 + 7).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16363987661999) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 101012269438 + ... + 101012269599.

Almost surely, 2^{16363987661997} is an apocalyptic number.

It is an amenable number.

16363987661997 is a deficient number, since it is larger than the sum of its proper divisors (8080981561601).

16363987661997 is an equidigital number, since it uses as much as digits as its factorization.

16363987661997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 202024539049 (or 202024539040 counting only the distinct ones).

The product of its digits is 3333197952, while the sum is 81.

The spelling of 16363987661997 in words is "sixteen trillion, three hundred sixty-three billion, nine hundred eighty-seven million, six hundred sixty-one thousand, nine hundred ninety-seven".