2155511566 has 32 divisors (see below), whose sum is σ = 3690217440. Its totient is φ = 935463936.

The previous prime is 2155511543. The next prime is 2155511647. The reversal of 2155511566 is 6651155512.

2155511566 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×2155511566² = 9292460222319544712, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 788490 + ... + 791218.

It is an arithmetic number, because the mean of its divisors is an integer number (115319295).

Almost surely, 2^2155511566 is an apocalyptic number.

2155511566 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

2155511566 is a deficient number, since it is larger than the sum of its proper divisors (1534705874).

2155511566 is a wasteful number, since it uses less digits than its factorization.

2155511566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4548.

The product of its digits is 45000, while the sum is 37.

The square root of 2155511566 is about 46427.4871816255. The cubic root of 2155511566 is about 1291.7648192320.

The spelling of 2155511566 in words is "two billion, one hundred fifty-five million, five hundred eleven thousand, five hundred sixty-six".