66660420 has 24 divisors (see below), whose sum is σ = 186649344. Its totient is φ = 17776096.

The previous prime is 66660401. The next prime is 66660427. The reversal of 66660420 is 2406666.

It is a super-2 number, since 2×66660420² = 8887223189152800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (66660427) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 555444 + ... + 555563.

It is an arithmetic number, because the mean of its divisors is an integer number (7777056).

Almost surely, 2^66660420 is an apocalyptic number.

66660420 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66660420 is an abundant number, since it is smaller than the sum of its proper divisors (119988924).

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

66660420 is a wasteful number, since it uses less digits than its factorization.

66660420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1111019 (or 1111017 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 30.

The square root of 66660420 is about 8164.5832716679. The cubic root of 66660420 is about 405.4674681465.

The spelling of 66660420 in words is "sixty-six million, six hundred sixty thousand, four hundred twenty".