1663926405555 has 8 divisors (see below), whose sum is σ = 2662282248912. Its totient is φ = 887427416288.

The previous prime is 1663926405551. The next prime is 1663926405577. The reversal of 1663926405555 is 5555046293661.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1663926405555 - 2² = 1663926405551 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1663926405495 and 1663926405504.

It is not an unprimeable number, because it can be changed into a prime (1663926405551) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55464213504 + ... + 55464213533.

It is an arithmetic number, because the mean of its divisors is an integer number (332785281114).

Almost surely, 2^{1663926405555} is an apocalyptic number.

1663926405555 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1663926405555 is a deficient number, since it is larger than the sum of its proper divisors (998355843357).

1663926405555 is a wasteful number, since it uses less digits than its factorization.

1663926405555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110928427045.

The product of its (nonzero) digits is 29160000, while the sum is 57.

The spelling of 1663926405555 in words is "one trillion, six hundred sixty-three billion, nine hundred twenty-six million, four hundred five thousand, five hundred fifty-five".