66895581 has 4 divisors (see below), whose sum is σ = 89194112. Its totient is φ = 44597052.

The previous prime is 66895579. The next prime is 66895583. The reversal of 66895581 is 18559866.

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 an interprime number because it is at equal distance from previous prime (66895579) and next prime (66895583).

It is not a de Polignac number, because 66895581 - 2¹ = 66895579 is a prime.

It is a super-2 number, since 2×66895581² = 8950037514655122, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66895581.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66895583) 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, 11149261 + ... + 11149266.

It is an arithmetic number, because the mean of its divisors is an integer number (22298528).

Almost surely, 2^66895581 is an apocalyptic number.

It is an amenable number.

66895581 is a deficient number, since it is larger than the sum of its proper divisors (22298531).

66895581 is a wasteful number, since it uses less digits than its factorization.

66895581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22298530.

The product of its digits is 518400, while the sum is 48.

The square root of 66895581 is about 8178.9718791545. The cubic root of 66895581 is about 405.9437039240.

It can be divided in two parts, 66895 and 581, that added together give a palindrome (67476).

The spelling of 66895581 in words is "sixty-six million, eight hundred ninety-five thousand, five hundred eighty-one".