66900381 has 4 divisors (see below), whose sum is σ = 89200512. Its totient is φ = 44600252.

The previous prime is 66900377. The next prime is 66900391. The reversal of 66900381 is 18300966.

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 a cyclic number.

It is not a de Polignac number, because 66900381 - 2² = 66900377 is a prime.

It is a super-2 number, since 2×66900381² = 8951321955890322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66900331) 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 3 ways as a sum of consecutive naturals, for example, 11150061 + ... + 11150066.

It is an arithmetic number, because the mean of its divisors is an integer number (22300128).

Almost surely, 2^66900381 is an apocalyptic number.

It is an amenable number.

66900381 is a deficient number, since it is larger than the sum of its proper divisors (22300131).

66900381 is a wasteful number, since it uses less digits than its factorization.

66900381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22300130.

The product of its (nonzero) digits is 7776, while the sum is 33.

The square root of 66900381 is about 8179.2653093050. The cubic root of 66900381 is about 405.9534130016.

The spelling of 66900381 in words is "sixty-six million, nine hundred thousand, three hundred eighty-one".