64446780385 has 16 divisors (see below), whose sum is σ = 83358933840. Its totient is φ = 47549260800.

The previous prime is 64446780373. The next prime is 64446780401. The reversal of 64446780385 is 58308764446.

It is a happy number.

64446780385 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 33570667729 + 30876112656 = 183223^2 + 175716^2 .

It is not a de Polignac number, because 64446780385 - 2⁵ = 64446780353 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 365716 + ... + 512485.

It is an arithmetic number, because the mean of its divisors is an integer number (5209933365).

Almost surely, 2^64446780385 is an apocalyptic number.

64446780385 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

64446780385 is a deficient number, since it is larger than the sum of its proper divisors (18912153455).

64446780385 is a wasteful number, since it uses less digits than its factorization.

64446780385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 879348.

The product of its (nonzero) digits is 15482880, while the sum is 55.

The spelling of 64446780385 in words is "sixty-four billion, four hundred forty-six million, seven hundred eighty thousand, three hundred eighty-five".