1395440640 has 264 divisors, whose sum is σ = 5276641968. Its totient is φ = 338165760.

The previous prime is 1395440623. The next prime is 1395440671. The reversal of 1395440640 is 460445931.

1395440640 is a `hidden beast` number, since 1 + 3 + 9 + 5 + 4 + 4 + 0 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (264).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1395440595 and 1395440604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 505504 + ... + 508256.

Almost surely, 2^1395440640 is an apocalyptic number.

1395440640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1395440640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2638320984).

1395440640 is an abundant number, since it is smaller than the sum of its proper divisors (3881201328).

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

1395440640 is a wasteful number, since it uses less digits than its factorization.

1395440640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2795 (or 2774 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The square root of 1395440640 is about 37355.5971709729. The cubic root of 1395440640 is about 1117.4732152792.

The spelling of 1395440640 in words is "one billion, three hundred ninety-five million, four hundred forty thousand, six hundred forty".