1399021568 has 112 divisors (see below), whose sum is σ = 3304909824. Its totient is φ = 579502080.

The previous prime is 1399021543. The next prime is 1399021571. The reversal of 1399021568 is 8651209931.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (112).

It is a super-2 number, since 2×1399021568² = 3914522695458357248, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1777271 + ... + 1778057.

Almost surely, 2^1399021568 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1399021568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1652454912).

1399021568 is an abundant number, since it is smaller than the sum of its proper divisors (1905888256).

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

1399021568 is an frugal number, since it uses more digits than its factorization.

1399021568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 851 (or 827 counting only the distinct ones).

The product of its (nonzero) digits is 116640, while the sum is 44.

The square root of 1399021568 is about 37403.4967349311. The cubic root of 1399021568 is about 1118.4282715702.

The spelling of 1399021568 in words is "one billion, three hundred ninety-nine million, twenty-one thousand, five hundred sixty-eight".