66001556 has 12 divisors (see below), whose sum is σ = 115674720. Its totient is φ = 32951640.

The previous prime is 66001549. The next prime is 66001597. The reversal of 66001556 is 65510066.

It is a super-2 number, since 2×66001556² = 8712410788842272, 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 3 ways as a sum of consecutive naturals, for example, 9176 + ... + 14703.

It is an arithmetic number, because the mean of its divisors is an integer number (9639560).

Almost surely, 2^66001556 is an apocalyptic number.

It is an amenable number.

66001556 is a deficient number, since it is larger than the sum of its proper divisors (49673164).

66001556 is a wasteful number, since it uses less digits than its factorization.

66001556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24574 (or 24572 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 29.

The square root of 66001556 is about 8124.1341692515. The cubic root of 66001556 is about 404.1271778804.

The spelling of 66001556 in words is "sixty-six million, one thousand, five hundred fifty-six".