648411221 has 4 divisors (see below), whose sum is σ = 669327744. Its totient is φ = 627494700.

The previous prime is 648411217. The next prime is 648411241. The reversal of 648411221 is 122114846.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 648411221 - 2² = 648411217 is a prime.

It is a super-2 number, since 2×648411221² = 840874223037421682, 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 (648411241) 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, 10458215 + ... + 10458276.

It is an arithmetic number, because the mean of its divisors is an integer number (167331936).

Almost surely, 2^648411221 is an apocalyptic number.

It is an amenable number.

648411221 is a deficient number, since it is larger than the sum of its proper divisors (20916523).

648411221 is a wasteful number, since it uses less digits than its factorization.

648411221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20916522.

The product of its digits is 3072, while the sum is 29.

The square root of 648411221 is about 25463.9199849513. The cubic root of 648411221 is about 865.5327538813.

The spelling of 648411221 in words is "six hundred forty-eight million, four hundred eleven thousand, two hundred twenty-one".