6540020667400 has 96 divisors (see below), whose sum is σ = 16588945025280. Its totient is φ = 2378035296000.

The previous prime is 6540020667359. The next prime is 6540020667407. The reversal of 6540020667400 is 47660200456.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is not an unprimeable number, because it can be changed into a prime (6540020667407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 37151590 + ... + 37327210.

It is an arithmetic number, because the mean of its divisors is an integer number (172801510680).

Almost surely, 2^{6540020667400} is an apocalyptic number.

It is an amenable number.

6540020667400 is an abundant number, since it is smaller than the sum of its proper divisors (10048924357880).

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

6540020667400 is a wasteful number, since it uses less digits than its factorization.

6540020667400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 192575 (or 192566 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 40.

Adding to 6540020667400 its reverse (47660200456), we get a palindrome (6587680867856).

The spelling of 6540020667400 in words is "six trillion, five hundred forty billion, twenty million, six hundred sixty-seven thousand, four hundred".