1166621655 has 16 divisors (see below), whose sum is σ = 1917044064. Its totient is φ = 605381760.

The previous prime is 1166621653. The next prime is 1166621671. The reversal of 1166621655 is 5561266611.

It is not a de Polignac number, because 1166621655 - 2¹ = 1166621653 is a prime.

It is a super-3 number, since 3×1166621655³ (a number of 28 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1166621653) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1050456 + ... + 1051565.

It is an arithmetic number, because the mean of its divisors is an integer number (119815254).

Almost surely, 2^1166621655 is an apocalyptic number.

1166621655 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1166621655 is a deficient number, since it is larger than the sum of its proper divisors (750422409).

1166621655 is a wasteful number, since it uses less digits than its factorization.

1166621655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2102066.

The product of its digits is 64800, while the sum is 39.

The square root of 1166621655 is about 34155.8436435114. The cubic root of 1166621655 is about 1052.7130608699.

The spelling of 1166621655 in words is "one billion, one hundred sixty-six million, six hundred twenty-one thousand, six hundred fifty-five".