16781215664408 has 32 divisors (see below), whose sum is σ = 33885379049760. Its totient is φ = 7745123424000.

The previous prime is 16781215664407. The next prime is 16781215664449. The reversal of 16781215664408 is 80446651218761.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16781215664401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17544533 + ... + 18476283.

It is an arithmetic number, because the mean of its divisors is an integer number (1058918095305).

Almost surely, 2^{16781215664408} is an apocalyptic number.

It is an amenable number.

16781215664408 is an abundant number, since it is smaller than the sum of its proper divisors (17104163385352).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

16781215664408 is a wasteful number, since it uses less digits than its factorization.

16781215664408 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1104947 (or 1104943 counting only the distinct ones).

The product of its (nonzero) digits is 15482880, while the sum is 59.

The spelling of 16781215664408 in words is "sixteen trillion, seven hundred eighty-one billion, two hundred fifteen million, six hundred sixty-four thousand, four hundred eight".