66502540 has 48 divisors (see below), whose sum is σ = 151576992. Its totient is φ = 24362496.

The previous prime is 66502537. The next prime is 66502547. The reversal of 66502540 is 4520566.

It is a junction number, because it is equal to n+sod(n) for n = 66502499 and 66502508.

It is not an unprimeable number, because it can be changed into a prime (66502547) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34687 + ... + 36553.

It is an arithmetic number, because the mean of its divisors is an integer number (3157854).

Almost surely, 2^66502540 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 66502540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (75788496).

66502540 is an abundant number, since it is smaller than the sum of its proper divisors (85074452).

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

66502540 is a wasteful number, since it uses less digits than its factorization.

66502540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2026 (or 2024 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 28.

The square root of 66502540 is about 8154.9089510552. The cubic root of 66502540 is about 405.1471090848.

The spelling of 66502540 in words is "sixty-six million, five hundred two thousand, five hundred forty".