55001521 has 2 divisors, whose sum is σ = 55001522. Its totient is φ = 55001520.

The previous prime is 55001519. The next prime is 55001539. The reversal of 55001521 is 12510055.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30647296 + 24354225 = 5536^2 + 4935^2 .

It is a cyclic number.

It is not a de Polignac number, because 55001521 - 2¹ = 55001519 is a prime.

Together with 55001519, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (55001591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27500760 + 27500761.

It is an arithmetic number, because the mean of its divisors is an integer number (27500761).

Almost surely, 2^55001521 is an apocalyptic number.

It is an amenable number.

55001521 is a deficient number, since it is larger than the sum of its proper divisors (1).

55001521 is an equidigital number, since it uses as much as digits as its factorization.

55001521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 250, while the sum is 19.

The square root of 55001521 is about 7416.3010321858. The cubic root of 55001521 is about 380.2987516745.

Adding to 55001521 its reverse (12510055), we get a palindrome (67511576).

It can be divided in two parts, 5500 and 1521, that added together give a triangular number (7021 = T₁₁₈).

The spelling of 55001521 in words is "fifty-five million, one thousand, five hundred twenty-one".