1391777664 has 64 divisors (see below), whose sum is σ = 3891504000. Its totient is φ = 439506432.

The previous prime is 1391777663. The next prime is 1391777687. The reversal of 1391777664 is 4667771931.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1391777663) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 88084 + ... + 102675.

It is an arithmetic number, because the mean of its divisors is an integer number (60804750).

Almost surely, 2^1391777664 is an apocalyptic number.

It is an amenable number.

1391777664 is an abundant number, since it is smaller than the sum of its proper divisors (2499726336).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1391777664 is a wasteful number, since it uses less digits than its factorization.

1391777664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 190795 (or 190783 counting only the distinct ones).

The product of its digits is 1333584, while the sum is 51.

The square root of 1391777664 is about 37306.5364782098. The cubic root of 1391777664 is about 1116.4945842895.

The spelling of 1391777664 in words is "one billion, three hundred ninety-one million, seven hundred seventy-seven thousand, six hundred sixty-four".