53071221 has 16 divisors (see below), whose sum is σ = 81114624. Its totient is φ = 30234864.

The previous prime is 53071211. The next prime is 53071223. The reversal of 53071221 is 12217035.

It is not a de Polignac number, because 53071221 - 2⁹ = 53070709 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (53071223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3646 + ... + 10928.

It is an arithmetic number, because the mean of its divisors is an integer number (5069664).

Almost surely, 2^53071221 is an apocalyptic number.

It is an amenable number.

53071221 is a deficient number, since it is larger than the sum of its proper divisors (28043403).

53071221 is a wasteful number, since it uses less digits than its factorization.

53071221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7640.

The product of its (nonzero) digits is 420, while the sum is 21.

The square root of 53071221 is about 7284.9997254633. Note that the first 3 decimals coincide. The cubic root of 53071221 is about 375.7967557264.

Adding to 53071221 its reverse (12217035), we get a palindrome (65288256).

The spelling of 53071221 in words is "fifty-three million, seventy-one thousand, two hundred twenty-one".