66658540 has 48 divisors (see below), whose sum is σ = 151351200. Its totient is φ = 24514560.

The previous prime is 66658519. The next prime is 66658567. The reversal of 66658540 is 4585666.

It is a junction number, because it is equal to n+sod(n) for n = 66658493 and 66658502.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 116455 + ... + 117025.

It is an arithmetic number, because the mean of its divisors is an integer number (3153150).

Almost surely, 2^66658540 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66658540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (75675600).

66658540 is an abundant number, since it is smaller than the sum of its proper divisors (84692660).

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

66658540 is a wasteful number, since it uses less digits than its factorization.

66658540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1042 (or 1040 counting only the distinct ones).

The product of its (nonzero) digits is 172800, while the sum is 40.

The square root of 66658540 is about 8164.4681394442. The cubic root of 66658540 is about 405.4636563593.

The spelling of 66658540 in words is "sixty-six million, six hundred fifty-eight thousand, five hundred forty".