66534557 has 8 divisors (see below), whose sum is σ = 68084280. Its totient is φ = 64995840.

The previous prime is 66534553. The next prime is 66534571. The reversal of 66534557 is 75543566.

It can be written as a sum of positive squares in 4 ways, for example, as 44809636 + 21724921 = 6694^2 + 4661^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66534557 - 2² = 66534553 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66534553) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10169 + ... + 15377.

It is an arithmetic number, because the mean of its divisors is an integer number (8510535).

Almost surely, 2^66534557 is an apocalyptic number.

It is an amenable number.

66534557 is a deficient number, since it is larger than the sum of its proper divisors (1549723).

66534557 is a wasteful number, since it uses less digits than its factorization.

66534557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5503.

The product of its digits is 378000, while the sum is 41.

The square root of 66534557 is about 8156.8717655729. The cubic root of 66534557 is about 405.2121166964.

Subtracting 66534557 from its reverse (75543566), we obtain a palindrome (9009009).

The spelling of 66534557 in words is "sixty-six million, five hundred thirty-four thousand, five hundred fifty-seven".