6401215550 has 24 divisors (see below), whose sum is σ = 11910510000. Its totient is φ = 2559572480.

The previous prime is 6401215549. The next prime is 6401215567. The reversal of 6401215550 is 555121046.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 128606 + ... + 171294.

It is an arithmetic number, because the mean of its divisors is an integer number (496271250).

Almost surely, 2^6401215550 is an apocalyptic number.

6401215550 is a deficient number, since it is larger than the sum of its proper divisors (5509294450).

6401215550 is a wasteful number, since it uses less digits than its factorization.

6401215550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45700 (or 45695 counting only the distinct ones).

The product of its (nonzero) digits is 6000, while the sum is 29.

The square root of 6401215550 is about 80007.5968268014. The cubic root of 6401215550 is about 1856.7530694065.

Adding to 6401215550 its reverse (555121046), we get a palindrome (6956336596).

The spelling of 6401215550 in words is "six billion, four hundred one million, two hundred fifteen thousand, five hundred fifty".