66437605 has 16 divisors (see below), whose sum is σ = 86027760. Its totient is φ = 48964608.

The previous prime is 66437603. The next prime is 66437621. The reversal of 66437605 is 50673466.

It can be written as a sum of positive squares in 8 ways, for example, as 29931841 + 36505764 = 5471^2 + 6042^2 .

It is a cyclic number.

It is not a de Polignac number, because 66437605 - 2¹ = 66437603 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66437603) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 65079 + ... + 66091.

It is an arithmetic number, because the mean of its divisors is an integer number (5376735).

Almost surely, 2^66437605 is an apocalyptic number.

66437605 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

66437605 is a deficient number, since it is larger than the sum of its proper divisors (19590155).

66437605 is a wasteful number, since it uses less digits than its factorization.

66437605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2040.

The product of its (nonzero) digits is 90720, while the sum is 37.

The square root of 66437605 is about 8150.9266344386. The cubic root of 66437605 is about 405.0152003643.

The spelling of 66437605 in words is "sixty-six million, four hundred thirty-seven thousand, six hundred five".