66948639 has 4 divisors (see below), whose sum is σ = 89264856. Its totient is φ = 44632424.

The previous prime is 66948631. The next prime is 66948643. The reversal of 66948639 is 93684966.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66948639 - 2³ = 66948631 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 66948591 and 66948600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66948631) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11158104 + ... + 11158109.

It is an arithmetic number, because the mean of its divisors is an integer number (22316214).

Almost surely, 2^66948639 is an apocalyptic number.

66948639 is a deficient number, since it is larger than the sum of its proper divisors (22316217).

66948639 is a wasteful number, since it uses less digits than its factorization.

66948639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22316216.

The product of its digits is 1679616, while the sum is 51.

The square root of 66948639 is about 8182.2147979627. The cubic root of 66948639 is about 406.0509998460.

The spelling of 66948639 in words is "sixty-six million, nine hundred forty-eight thousand, six hundred thirty-nine".