66420544 has 28 divisors (see below), whose sum is σ = 132632704. Its totient is φ = 33001344.

The previous prime is 66420539. The next prime is 66420553. The reversal of 66420544 is 44502466.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7249 + ... + 13615.

Almost surely, 2^66420544 is an apocalyptic number.

66420544 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

66420544 is a deficient number, since it is larger than the sum of its proper divisors (66212160).

66420544 is a wasteful number, since it uses less digits than its factorization.

66420544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6542 (or 6532 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 31.

The square root of 66420544 is about 8149.8799991166. The cubic root of 66420544 is about 404.9805284547.

The spelling of 66420544 in words is "sixty-six million, four hundred twenty thousand, five hundred forty-four".