16781215664407 has 2 divisors, whose sum is σ = 16781215664408. Its totient is φ = 16781215664406.

The previous prime is 16781215664401. The next prime is 16781215664449. The reversal of 16781215664407 is 70446651218761.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 16781215664407 - 2¹⁵ = 16781215631639 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16781215664401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8390607832203 + 8390607832204.

It is an arithmetic number, because the mean of its divisors is an integer number (8390607832204).

Almost surely, 2^{16781215664407} is an apocalyptic number.

16781215664407 is a deficient number, since it is larger than the sum of its proper divisors (1).

16781215664407 is an equidigital number, since it uses as much as digits as its factorization.

16781215664407 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13547520, while the sum is 58.

The spelling of 16781215664407 in words is "sixteen trillion, seven hundred eighty-one billion, two hundred fifteen million, six hundred sixty-four thousand, four hundred seven".