66664536 has 16 divisors (see below), whose sum is σ = 166661400. Its totient is φ = 22221504.

The previous prime is 66664529. The next prime is 66664547. The reversal of 66664536 is 63546666.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1388821 + ... + 1388868.

Almost surely, 2^66664536 is an apocalyptic number.

It is an amenable number.

66664536 is an abundant number, since it is smaller than the sum of its proper divisors (99996864).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66664536 is a wasteful number, since it uses less digits than its factorization.

66664536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2777698 (or 2777694 counting only the distinct ones).

The product of its digits is 466560, while the sum is 42.

The square root of 66664536 is about 8164.8353320811. The cubic root of 66664536 is about 405.4758132772.

It can be divided in two parts, 6666 and 4536, that multiplied together give a triangular number (30236976 = T₇₇₇₆).

The spelling of 66664536 in words is "sixty-six million, six hundred sixty-four thousand, five hundred thirty-six".