64866661 has 8 divisors (see below), whose sum is σ = 68170784. Its totient is φ = 61644240.

The previous prime is 64866631. The next prime is 64866667. The reversal of 64866661 is 16666846.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 64866661 - 2⁵ = 64866629 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64866667) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18795 + ... + 21976.

It is an arithmetic number, because the mean of its divisors is an integer number (8521348).

Almost surely, 2^64866661 is an apocalyptic number.

It is an amenable number.

64866661 is a deficient number, since it is larger than the sum of its proper divisors (3304123).

64866661 is a wasteful number, since it uses less digits than its factorization.

64866661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40851.

The product of its digits is 248832, while the sum is 43.

The square root of 64866661 is about 8053.9841693413. The cubic root of 64866661 is about 401.7974545444.

The spelling of 64866661 in words is "sixty-four million, eight hundred sixty-six thousand, six hundred sixty-one".