52405221 has 24 divisors (see below), whose sum is σ = 79297792. Its totient is φ = 30729600.

The previous prime is 52405217. The next prime is 52405229. The reversal of 52405221 is 12250425.

52405221 = 678² + 679² + ... + 776².

It is a happy number.

It is not a de Polignac number, because 52405221 - 2² = 52405217 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (52405229) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8925 + ... + 13581.

Almost surely, 2^52405221 is an apocalyptic number.

It is an amenable number.

52405221 is a deficient number, since it is larger than the sum of its proper divisors (26892571).

52405221 is a wasteful number, since it uses less digits than its factorization.

52405221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4713 (or 4702 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 21.

The square root of 52405221 is about 7239.1450462054. The cubic root of 52405221 is about 374.2181541562.

Adding to 52405221 its reverse (12250425), we get a palindrome (64655646).

The spelling of 52405221 in words is "fifty-two million, four hundred five thousand, two hundred twenty-one".