6440155400 has 96 divisors (see below), whose sum is σ = 17129945280. Its totient is φ = 2205792000.

The previous prime is 6440155387. The next prime is 6440155409. The reversal of 6440155400 is 45510446.

It is a super-2 number, since 2×6440155400² = 82951203152298320000, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (6440155409) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1931735 + ... + 1935065.

It is an arithmetic number, because the mean of its divisors is an integer number (178436930).

Almost surely, 2^6440155400 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 6440155400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8564972640).

6440155400 is an abundant number, since it is smaller than the sum of its proper divisors (10689789880).

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

6440155400 is a wasteful number, since it uses less digits than its factorization.

6440155400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4735 (or 4726 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 29.

The square root of 6440155400 is about 80250.5788141120. The cubic root of 6440155400 is about 1860.5104584247.

Adding to 6440155400 its reverse (45510446), we get a palindrome (6485665846).

The spelling of 6440155400 in words is "six billion, four hundred forty million, one hundred fifty-five thousand, four hundred".