64477978783 has 4 divisors (see below), whose sum is σ = 65849850720. Its totient is φ = 63106106848.

The previous prime is 64477978771. The next prime is 64477978793. The reversal of 64477978783 is 38787977446.

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 64477978783 - 2¹³ = 64477970591 is a prime.

It is a super-2 number, since 2×64477978783² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64477978793) 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, 685935898 + ... + 685935991.

It is an arithmetic number, because the mean of its divisors is an integer number (16462462680).

Almost surely, 2^64477978783 is an apocalyptic number.

64477978783 is a deficient number, since it is larger than the sum of its proper divisors (1371871937).

64477978783 is a wasteful number, since it uses less digits than its factorization.

64477978783 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1371871936.

The product of its digits is 398297088, while the sum is 70.

The spelling of 64477978783 in words is "sixty-four billion, four hundred seventy-seven million, nine hundred seventy-eight thousand, seven hundred eighty-three".