66543645 has 32 divisors (see below), whose sum is σ = 122335488. Its totient is φ = 30256128.

The previous prime is 66543637. The next prime is 66543647. The reversal of 66543645 is 54634566.

It is not a de Polignac number, because 66543645 - 2³ = 66543637 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66543647) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 19077 + ... + 22293.

It is an arithmetic number, because the mean of its divisors is an integer number (3822984).

Almost surely, 2^66543645 is an apocalyptic number.

It is an amenable number.

66543645 is a deficient number, since it is larger than the sum of its proper divisors (55791843).

66543645 is a wasteful number, since it uses less digits than its factorization.

66543645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3429.

The product of its digits is 259200, while the sum is 39.

The square root of 66543645 is about 8157.4288228583. The cubic root of 66543645 is about 405.2305652552.

The spelling of 66543645 in words is "sixty-six million, five hundred forty-three thousand, six hundred forty-five".