6403261440 has 352 divisors, whose sum is σ = 22178344320. Its totient is φ = 1571291136.

The previous prime is 6403261427. The next prime is 6403261453. The reversal of 6403261440 is 441623046.

It is an interprime number because it is at equal distance from previous prime (6403261427) and next prime (6403261453).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 6403261398 and 6403261407.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 10797784 + ... + 10798376.

It is an arithmetic number, because the mean of its divisors is an integer number (63006660).

Almost surely, 2^6403261440 is an apocalyptic number.

6403261440 is a gapful number since it is divisible by the number (60) 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 6403261440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11089172160).

6403261440 is an abundant number, since it is smaller than the sum of its proper divisors (15775082880).

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

6403261440 is a wasteful number, since it uses less digits than its factorization.

6403261440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 677 (or 659 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 30.

The square root of 6403261440 is about 80020.3814037399. The cubic root of 6403261440 is about 1856.9508603769.

Adding to 6403261440 its reverse (441623046), we get a palindrome (6844884486).

The spelling of 6403261440 in words is "six billion, four hundred three million, two hundred sixty-one thousand, four hundred forty".