64778825 has 6 divisors (see below), whose sum is σ = 80325774. Its totient is φ = 51823040.

The previous prime is 64778821. The next prime is 64778827. The reversal of 64778825 is 52887746.

It can be written as a sum of positive squares in 3 ways, for example, as 12823561 + 51955264 = 3581^2 + 7208^2 .

It is not a de Polignac number, because 64778825 - 2² = 64778821 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 64778825.

It is not an unprimeable number, because it can be changed into a prime (64778821) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1295552 + ... + 1295601.

It is an arithmetic number, because the mean of its divisors is an integer number (13387629).

Almost surely, 2^64778825 is an apocalyptic number.

It is an amenable number.

64778825 is a deficient number, since it is larger than the sum of its proper divisors (15546949).

64778825 is a wasteful number, since it uses less digits than its factorization.

64778825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2591163 (or 2591158 counting only the distinct ones).

The product of its digits is 752640, while the sum is 47.

The square root of 64778825 is about 8048.5293687729. The cubic root of 64778825 is about 401.6160145338.

The spelling of 64778825 in words is "sixty-four million, seven hundred seventy-eight thousand, eight hundred twenty-five".