66900081 has 4 divisors (see below), whose sum is σ = 89200112. Its totient is φ = 44600052.

The previous prime is 66900059. The next prime is 66900089. The reversal of 66900081 is 18000966.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 66900081 - 2⁶ = 66900017 is a prime.

It is a super-2 number, since 2×66900081² = 8951241675613122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66900089) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11150011 + ... + 11150016.

It is an arithmetic number, because the mean of its divisors is an integer number (22300028).

Almost surely, 2^66900081 is an apocalyptic number.

It is an amenable number.

66900081 is a deficient number, since it is larger than the sum of its proper divisors (22300031).

66900081 is a wasteful number, since it uses less digits than its factorization.

66900081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22300030.

The product of its (nonzero) digits is 2592, while the sum is 30.

The square root of 66900081 is about 8179.2469702290. The cubic root of 66900081 is about 405.9528061979.

The spelling of 66900081 in words is "sixty-six million, nine hundred thousand, eighty-one".