6421456540 has 24 divisors (see below), whose sum is σ = 13655759040. Its totient is φ = 2536068288.

The previous prime is 6421456513. The next prime is 6421456553. The reversal of 6421456540 is 456541246.

It is a self number, because there is not a number n which added to its sum of digits gives 6421456540.

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, 2030527 + ... + 2033686.

It is an arithmetic number, because the mean of its divisors is an integer number (568989960).

Almost surely, 2^6421456540 is an apocalyptic number.

It is an amenable number.

6421456540 is an abundant number, since it is smaller than the sum of its proper divisors (7234302500).

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

6421456540 is a wasteful number, since it uses less digits than its factorization.

6421456540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4064301 (or 4064299 counting only the distinct ones).

The product of its (nonzero) digits is 115200, while the sum is 37.

The square root of 6421456540 is about 80133.9911647985. The cubic root of 6421456540 is about 1858.7080614859.

Adding to 6421456540 its reverse (456541246), we get a palindrome (6877997786).

The spelling of 6421456540 in words is "six billion, four hundred twenty-one million, four hundred fifty-six thousand, five hundred forty".