66532861 has 4 divisors (see below), whose sum is σ = 67788252. Its totient is φ = 65277472.

The previous prime is 66532853. The next prime is 66532867. The reversal of 66532861 is 16823566.

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

It can be written as a sum of positive squares in 2 ways, for example, as 31427236 + 35105625 = 5606^2 + 5925^2 .

It is a cyclic number.

It is not a de Polignac number, because 66532861 - 2³ = 66532853 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66532861.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66532867) 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, 627616 + ... + 627721.

It is an arithmetic number, because the mean of its divisors is an integer number (16947063).

Almost surely, 2^66532861 is an apocalyptic number.

It is an amenable number.

66532861 is a deficient number, since it is larger than the sum of its proper divisors (1255391).

66532861 is a wasteful number, since it uses less digits than its factorization.

66532861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1255390.

The product of its digits is 51840, while the sum is 37.

The square root of 66532861 is about 8156.7678034869. The cubic root of 66532861 is about 405.2086736455.

The spelling of 66532861 in words is "sixty-six million, five hundred thirty-two thousand, eight hundred sixty-one".