64661847 has 4 divisors (see below), whose sum is σ = 86215800. Its totient is φ = 43107896.

The previous prime is 64661813. The next prime is 64661873. The reversal of 64661847 is 74816646.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 64661847 - 2⁷ = 64661719 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 64661799 and 64661808.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64661147) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10776972 + ... + 10776977.

It is an arithmetic number, because the mean of its divisors is an integer number (21553950).

Almost surely, 2^64661847 is an apocalyptic number.

64661847 is a deficient number, since it is larger than the sum of its proper divisors (21553953).

64661847 is a wasteful number, since it uses less digits than its factorization.

64661847 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21553952.

The product of its digits is 193536, while the sum is 42.

The square root of 64661847 is about 8041.2590432096. The cubic root of 64661847 is about 401.3741219831.

The spelling of 64661847 in words is "sixty-four million, six hundred sixty-one thousand, eight hundred forty-seven".