66406535 has 16 divisors (see below), whose sum is σ = 87647616. Its totient is φ = 47993088.

The previous prime is 66406519. The next prime is 66406537. The reversal of 66406535 is 53560466.

It is not a de Polignac number, because 66406535 - 2⁴ = 66406519 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66406495 and 66406504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66406537) 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, 7814 + ... + 13923.

It is an arithmetic number, because the mean of its divisors is an integer number (5477976).

Almost surely, 2^66406535 is an apocalyptic number.

66406535 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

66406535 is a deficient number, since it is larger than the sum of its proper divisors (21241081).

66406535 is a wasteful number, since it uses less digits than its factorization.

66406535 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21802.

The product of its (nonzero) digits is 64800, while the sum is 35.

The square root of 66406535 is about 8149.0204932863. The cubic root of 66406535 is about 404.9520544777.

The spelling of 66406535 in words is "sixty-six million, four hundred six thousand, five hundred thirty-five".