1399978406864 has 40 divisors (see below), whose sum is σ = 2872109262528. Its totient is φ = 658791636480.

The previous prime is 1399978406863. The next prime is 1399978406899. The reversal of 1399978406864 is 4686048799931.

It is a junction number, because it is equal to n+sod(n) for n = 1399978406791 and 1399978406800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1399978406863) 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, 10681859 + ... + 10812125.

Almost surely, 2^{1399978406864} is an apocalyptic number.

It is an amenable number.

1399978406864 is an abundant number, since it is smaller than the sum of its proper divisors (1472130855664).

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

1399978406864 is a wasteful number, since it uses less digits than its factorization.

1399978406864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169803 (or 169797 counting only the distinct ones).

The product of its (nonzero) digits is 564350976, while the sum is 74.

The spelling of 1399978406864 in words is "one trillion, three hundred ninety-nine billion, nine hundred seventy-eight million, four hundred six thousand, eight hundred sixty-four".