66081851 has 12 divisors (see below), whose sum is σ = 73176600. Its totient is φ = 59627040.

The previous prime is 66081823. The next prime is 66081857. The reversal of 66081851 is 15818066.

It is not a de Polignac number, because 66081851 - 2²² = 61887547 is a prime.

It is a super-2 number, since 2×66081851² = 8733622063172402, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66081857) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14855 + ... + 18783.

It is an arithmetic number, because the mean of its divisors is an integer number (6098050).

Almost surely, 2^66081851 is an apocalyptic number.

66081851 is a deficient number, since it is larger than the sum of its proper divisors (7094749).

66081851 is a wasteful number, since it uses less digits than its factorization.

66081851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4090 (or 4079 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 35.

The square root of 66081851 is about 8129.0744245578. The cubic root of 66081851 is about 404.2909934210.

The spelling of 66081851 in words is "sixty-six million, eighty-one thousand, eight hundred fifty-one".