6400435521 has 4 divisors (see below), whose sum is σ = 8533914032. Its totient is φ = 4266957012.

The previous prime is 6400435511. The next prime is 6400435537. The reversal of 6400435521 is 1255340046.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a de Polignac number, because none of the positive numbers 2^k-6400435521 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (6400435511) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1066739251 + ... + 1066739256.

It is an arithmetic number, because the mean of its divisors is an integer number (2133478508).

Almost surely, 2^6400435521 is an apocalyptic number.

It is an amenable number.

6400435521 is a deficient number, since it is larger than the sum of its proper divisors (2133478511).

6400435521 is a wasteful number, since it uses less digits than its factorization.

6400435521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2133478510.

The product of its (nonzero) digits is 14400, while the sum is 30.

The square root of 6400435521 is about 80002.7219599433. The cubic root of 6400435521 is about 1856.6776472692.

Adding to 6400435521 its reverse (1255340046), we get a palindrome (7655775567).

The spelling of 6400435521 in words is "six billion, four hundred million, four hundred thirty-five thousand, five hundred twenty-one".