64778743 has 4 divisors (see below), whose sum is σ = 64940688. Its totient is φ = 64616800.

The previous prime is 64778731. The next prime is 64778783. The reversal of 64778743 is 34787746.

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 64778743 - 2⁵ = 64778711 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 64778693 and 64778702.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64778723) 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, 80371 + ... + 81172.

It is an arithmetic number, because the mean of its divisors is an integer number (16235172).

Almost surely, 2^64778743 is an apocalyptic number.

64778743 is a deficient number, since it is larger than the sum of its proper divisors (161945).

64778743 is a wasteful number, since it uses less digits than its factorization.

64778743 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161944.

The product of its digits is 790272, while the sum is 46.

The square root of 64778743 is about 8048.5242746730. The cubic root of 64778743 is about 401.6158450724.

The spelling of 64778743 in words is "sixty-four million, seven hundred seventy-eight thousand, seven hundred forty-three".