66547220 has 12 divisors (see below), whose sum is σ = 139749204. Its totient is φ = 26618880.

The previous prime is 66547189. The next prime is 66547237. The reversal of 66547220 is 2274566.

It can be written as a sum of positive squares in 2 ways, for example, as 7595536 + 58951684 = 2756^2 + 7678^2 .

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

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, 1663661 + ... + 1663700.

It is an arithmetic number, because the mean of its divisors is an integer number (11645767).

Almost surely, 2^66547220 is an apocalyptic number.

It is an amenable number.

66547220 is an abundant number, since it is smaller than the sum of its proper divisors (73201984).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66547220 is a wasteful number, since it uses less digits than its factorization.

66547220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3327370 (or 3327368 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 32.

The square root of 66547220 is about 8157.6479453333. The cubic root of 66547220 is about 405.2378220129.

The spelling of 66547220 in words is "sixty-six million, five hundred forty-seven thousand, two hundred twenty".