53217021 has 32 divisors (see below), whose sum is σ = 88276608. Its totient is φ = 28016640.

The previous prime is 53216983. The next prime is 53217023. The reversal of 53217021 is 12071235.

It is not a de Polignac number, because 53217021 - 2⁹ = 53216509 is a prime.

It is a super-2 number, since 2×53217021² = 5664102648228882, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (53217023) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3645 + ... + 10941.

It is an arithmetic number, because the mean of its divisors is an integer number (2758644).

Almost surely, 2^53217021 is an apocalyptic number.

53217021 is a gapful number since it is divisible by the number (51) formed by its first and last digit.

It is an amenable number.

53217021 is a deficient number, since it is larger than the sum of its proper divisors (35059587).

53217021 is a wasteful number, since it uses less digits than its factorization.

53217021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7341.

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

The square root of 53217021 is about 7294.9997258396. Note that the first 3 decimals coincide. The cubic root of 53217021 is about 376.1405771507.

Adding to 53217021 its reverse (12071235), we get a palindrome (65288256).

The spelling of 53217021 in words is "fifty-three million, two hundred seventeen thousand, twenty-one".