1399664640 has 416 divisors, whose sum is σ = 5189817600. Its totient is φ = 318504960.

The previous prime is 1399664569. The next prime is 1399664647. The reversal of 1399664640 is 464669931.

It is a super-2 number, since 2×1399664640² = 3918122208932659200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 1399664640.

It is not an unprimeable number, because it can be changed into a prime (1399664647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 12840906 + ... + 12841014.

Almost surely, 2^1399664640 is an apocalyptic number.

1399664640 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 1399664640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2594908800).

1399664640 is an abundant number, since it is smaller than the sum of its proper divisors (3790152960).

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

1399664640 is a wasteful number, since it uses less digits than its factorization.

1399664640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171 (or 149 counting only the distinct ones).

The product of its (nonzero) digits is 839808, while the sum is 48.

The square root of 1399664640 is about 37412.0921628289. The cubic root of 1399664640 is about 1118.5996102996.

The spelling of 1399664640 in words is "one billion, three hundred ninety-nine million, six hundred sixty-four thousand, six hundred forty".