6402136520 has 128 divisors (see below), whose sum is σ = 15718510080. Its totient is φ = 2332800000.

The previous prime is 6402136513. The next prime is 6402136547. The reversal of 6402136520 is 256312046.

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, 23623985 + ... + 23624255.

It is an arithmetic number, because the mean of its divisors is an integer number (122800860).

Almost surely, 2^6402136520 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 6402136520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7859255040).

6402136520 is an abundant number, since it is smaller than the sum of its proper divisors (9316373560).

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

6402136520 is a wasteful number, since it uses less digits than its factorization.

6402136520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 727 (or 723 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 29.

The square root of 6402136520 is about 80013.3521357529. The cubic root of 6402136520 is about 1856.8421114464.

Adding to 6402136520 its reverse (256312046), we get a palindrome (6658448566).

The spelling of 6402136520 in words is "six billion, four hundred two million, one hundred thirty-six thousand, five hundred twenty".