66538020 has 24 divisors (see below), whose sum is σ = 186306624. Its totient is φ = 17743456.

The previous prime is 66538009. The next prime is 66538033. The reversal of 66538020 is 2083566.

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

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 554424 + ... + 554543.

It is an arithmetic number, because the mean of its divisors is an integer number (7762776).

Almost surely, 2^66538020 is an apocalyptic number.

66538020 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66538020 is an abundant number, since it is smaller than the sum of its proper divisors (119768604).

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

66538020 is a wasteful number, since it uses less digits than its factorization.

66538020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1108979 (or 1108977 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 30.

The square root of 66538020 is about 8157.0840378165. The cubic root of 66538020 is about 405.2191467535.

The spelling of 66538020 in words is "sixty-six million, five hundred thirty-eight thousand, twenty".