66515394 has 32 divisors (see below), whose sum is σ = 146341440. Its totient is φ = 20153760.

The previous prime is 66515369. The next prime is 66515399. The reversal of 66515394 is 49351566.

It is not an unprimeable number, because it can be changed into a prime (66515399) 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, 3822 + ... + 12150.

It is an arithmetic number, because the mean of its divisors is an integer number (4573170).

Almost surely, 2^66515394 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66515394, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (73170720).

66515394 is an abundant number, since it is smaller than the sum of its proper divisors (79826046).

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

66515394 is a wasteful number, since it uses less digits than its factorization.

66515394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8367 (or 8345 counting only the distinct ones).

The product of its digits is 97200, while the sum is 39.

The square root of 66515394 is about 8155.6970272319. The cubic root of 66515394 is about 405.1732104710.

The spelling of 66515394 in words is "sixty-six million, five hundred fifteen thousand, three hundred ninety-four".