648121855 has 8 divisors (see below), whose sum is σ = 823496112. Its totient is φ = 487997568.

The previous prime is 648121829. The next prime is 648121879. The reversal of 648121855 is 558121846.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 648121855 - 2¹⁵ = 648089087 is a prime.

It is a Duffinian number.

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, 3812397 + ... + 3812566.

It is an arithmetic number, because the mean of its divisors is an integer number (102937014).

Almost surely, 2^648121855 is an apocalyptic number.

648121855 is a deficient number, since it is larger than the sum of its proper divisors (175374257).

648121855 is a wasteful number, since it uses less digits than its factorization.

648121855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7624985.

The product of its digits is 76800, while the sum is 40.

The square root of 648121855 is about 25458.2374684502. The cubic root of 648121855 is about 865.4039811679.

Subtracting from 648121855 its reverse (558121846), we obtain a palindrome (90000009).

The spelling of 648121855 in words is "six hundred forty-eight million, one hundred twenty-one thousand, eight hundred fifty-five".