66783538 has 8 divisors (see below), whose sum is σ = 100940400. Its totient is φ = 33136740.

The previous prime is 66783533. The next prime is 66783571. The reversal of 66783538 is 83538766.

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

It is not an unprimeable number, because it can be changed into a prime (66783533) 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, 127188 + ... + 127711.

It is an arithmetic number, because the mean of its divisors is an integer number (12617550).

Almost surely, 2^66783538 is an apocalyptic number.

66783538 is a deficient number, since it is larger than the sum of its proper divisors (34156862).

66783538 is a wasteful number, since it uses less digits than its factorization.

66783538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 255032.

The product of its digits is 725760, while the sum is 46.

The square root of 66783538 is about 8172.1195537021. The cubic root of 66783538 is about 405.7169397315.

It can be divided in two parts, 667 and 83538, that multiplied together give a triangular number (55719846 = T₁₀₅₅₆).

The spelling of 66783538 in words is "sixty-six million, seven hundred eighty-three thousand, five hundred thirty-eight".