55020521 has 4 divisors (see below), whose sum is σ = 56300112. Its totient is φ = 53740932.

The previous prime is 55020499. The next prime is 55020529. The reversal of 55020521 is 12502055.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55020521 is a prime.

It is a super-2 number, since 2×55020521² = 6054515462222882, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 55020493 and 55020502.

It is not an unprimeable number, because it can be changed into a prime (55020529) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 639731 + ... + 639816.

It is an arithmetic number, because the mean of its divisors is an integer number (14075028).

Almost surely, 2^55020521 is an apocalyptic number.

It is an amenable number.

55020521 is a deficient number, since it is larger than the sum of its proper divisors (1279591).

55020521 is a wasteful number, since it uses less digits than its factorization.

55020521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1279590.

The product of its (nonzero) digits is 500, while the sum is 20.

The square root of 55020521 is about 7417.5818836060. The cubic root of 55020521 is about 380.3425373995.

Adding to 55020521 its reverse (12502055), we get a palindrome (67522576).

The spelling of 55020521 in words is "fifty-five million, twenty thousand, five hundred twenty-one".