648855421 has 4 divisors (see below), whose sum is σ = 666392092. Its totient is φ = 631318752.

The previous prime is 648855349. The next prime is 648855437. The reversal of 648855421 is 124558846.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 568107225 + 80748196 = 23835^2 + 8986^2 .

It is a cyclic number.

It is not a de Polignac number, because 648855421 - 2¹⁹ = 648331133 is a prime.

It is a super-2 number, since 2×648855421² = 842026714722174482, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (648855481) 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, 8768280 + ... + 8768353.

It is an arithmetic number, because the mean of its divisors is an integer number (166598023).

Almost surely, 2^648855421 is an apocalyptic number.

It is an amenable number.

648855421 is a deficient number, since it is larger than the sum of its proper divisors (17536671).

648855421 is a wasteful number, since it uses less digits than its factorization.

648855421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17536670.

The product of its digits is 307200, while the sum is 43.

The square root of 648855421 is about 25472.6406365732. The cubic root of 648855421 is about 865.7303557916.

The spelling of 648855421 in words is "six hundred forty-eight million, eight hundred fifty-five thousand, four hundred twenty-one".