16661725315427 has 2 divisors, whose sum is σ = 16661725315428. Its totient is φ = 16661725315426.

The previous prime is 16661725315409. The next prime is 16661725315447. The reversal of 16661725315427 is 72451352716661.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 16661725315427 - 2⁸ = 16661725315171 is a prime.

It is a super-2 number, since 2×16661725315427² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (16661725315447) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8330862657713 + 8330862657714.

It is an arithmetic number, because the mean of its divisors is an integer number (8330862657714).

Almost surely, 2^{16661725315427} is an apocalyptic number.

16661725315427 is a deficient number, since it is larger than the sum of its proper divisors (1).

16661725315427 is an equidigital number, since it uses as much as digits as its factorization.

16661725315427 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12700800, while the sum is 56.

The spelling of 16661725315427 in words is "sixteen trillion, six hundred sixty-one billion, seven hundred twenty-five million, three hundred fifteen thousand, four hundred twenty-seven".