1666613655 has 48 divisors (see below), whose sum is σ = 3371756544. Its totient is φ = 745663680.

The previous prime is 1666613623. The next prime is 1666613659. The reversal of 1666613655 is 5563166661.

It is not a de Polignac number, because 1666613655 - 2⁵ = 1666613623 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 1666613655.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666613659) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 41481 + ... + 71090.

It is an arithmetic number, because the mean of its divisors is an integer number (70244928).

Almost surely, 2^1666613655 is an apocalyptic number.

1666613655 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1666613655 is an abundant number, since it is smaller than the sum of its proper divisors (1705142889).

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

1666613655 is a wasteful number, since it uses less digits than its factorization.

1666613655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112636 (or 112633 counting only the distinct ones).

The product of its digits is 583200, while the sum is 45.

The square root of 1666613655 is about 40824.1797835547. The cubic root of 1666613655 is about 1185.6185309073.

The spelling of 1666613655 in words is "one billion, six hundred sixty-six million, six hundred thirteen thousand, six hundred fifty-five".