55120521 has 16 divisors (see below), whose sum is σ = 74390400. Its totient is φ = 36302208.

The previous prime is 55120469. The next prime is 55120531. The reversal of 55120521 is 12502155.

It is not a de Polignac number, because 55120521 - 2¹⁹ = 54596233 is a prime.

It is a super-2 number, since 2×55120521² = 6076543670622882, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (55120531) 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, 134565 + ... + 134973.

It is an arithmetic number, because the mean of its divisors is an integer number (4649400).

Almost surely, 2^55120521 is an apocalyptic number.

It is an amenable number.

55120521 is a deficient number, since it is larger than the sum of its proper divisors (19269879).

55120521 is a wasteful number, since it uses less digits than its factorization.

With its predecessor (55120520) it forms an eRAP, since the sums of their prime factors are consecutive (847 and 848).

55120521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 848.

The product of its (nonzero) digits is 500, while the sum is 21.

The square root of 55120521 is about 7424.3195647817. The cubic root of 55120521 is about 380.5728225963.

Adding to 55120521 its reverse (12502155), we get a palindrome (67622676).

The spelling of 55120521 in words is "fifty-five million, one hundred twenty thousand, five hundred twenty-one".