66643415 has 16 divisors (see below), whose sum is σ = 83030400. Its totient is φ = 51313920.

The previous prime is 66643403. The next prime is 66643427. The reversal of 66643415 is 51434666.

It is an interprime number because it is at equal distance from previous prime (66643403) and next prime (66643427).

It is not a de Polignac number, because 66643415 - 2¹⁴ = 66627031 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12011 + ... + 16659.

It is an arithmetic number, because the mean of its divisors is an integer number (5189400).

Almost surely, 2^66643415 is an apocalyptic number.

66643415 is a deficient number, since it is larger than the sum of its proper divisors (16386985).

66643415 is a wasteful number, since it uses less digits than its factorization.

66643415 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4762.

The product of its digits is 51840, while the sum is 35.

The square root of 66643415 is about 8163.5418171282. The cubic root of 66643415 is about 405.4329871122.

The spelling of 66643415 in words is "sixty-six million, six hundred forty-three thousand, four hundred fifteen".