66731537 has 16 divisors (see below), whose sum is σ = 69888000. Its totient is φ = 63679824.

The previous prime is 66731519. The next prime is 66731549. The reversal of 66731537 is 73513766.

It is a cyclic number.

It is not a de Polignac number, because 66731537 - 2¹⁰ = 66730513 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 66731537.

It is not an unprimeable number, because it can be changed into a prime (66731507) 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, 480014 + ... + 480152.

It is an arithmetic number, because the mean of its divisors is an integer number (4368000).

Almost surely, 2^66731537 is an apocalyptic number.

It is an amenable number.

66731537 is a deficient number, since it is larger than the sum of its proper divisors (3156463).

66731537 is a wasteful number, since it uses less digits than its factorization.

66731537 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 380.

The product of its digits is 79380, while the sum is 38.

The square root of 66731537 is about 8168.9373237894. The cubic root of 66731537 is about 405.6116085601.

The spelling of 66731537 in words is "sixty-six million, seven hundred thirty-one thousand, five hundred thirty-seven".