66542415 has 16 divisors (see below), whose sum is σ = 106579968. Its totient is φ = 35451936.

The previous prime is 66542393. The next prime is 66542417. The reversal of 66542415 is 51424566.

It is not a de Polignac number, because 66542415 - 2¹¹ = 66540367 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66542417) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18234 + ... + 21576.

It is an arithmetic number, because the mean of its divisors is an integer number (6661248).

Almost surely, 2^66542415 is an apocalyptic number.

66542415 is a deficient number, since it is larger than the sum of its proper divisors (40037553).

66542415 is a wasteful number, since it uses less digits than its factorization.

66542415 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4678.

The product of its digits is 28800, while the sum is 33.

The square root of 66542415 is about 8157.3534311074. The cubic root of 66542415 is about 405.2280684644.

The spelling of 66542415 in words is "sixty-six million, five hundred forty-two thousand, four hundred fifteen".