55520557 has 2 divisors, whose sum is σ = 55520558. Its totient is φ = 55520556.

The previous prime is 55520539. The next prime is 55520573. The reversal of 55520557 is 75502555.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 52794756 + 2725801 = 7266^2 + 1651^2 .

It is a cyclic number.

It is not a de Polignac number, because 55520557 - 2¹¹ = 55518509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55520537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27760278 + 27760279.

It is an arithmetic number, because the mean of its divisors is an integer number (27760279).

Almost surely, 2^55520557 is an apocalyptic number.

It is an amenable number.

55520557 is a deficient number, since it is larger than the sum of its proper divisors (1).

55520557 is an equidigital number, since it uses as much as digits as its factorization.

55520557 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 43750, while the sum is 34.

The square root of 55520557 is about 7451.2117806435. The cubic root of 55520557 is about 381.4912706626.

It can be divided in two parts, 555 and 20557, that added together give a palindrome (21112).

The spelling of 55520557 in words is "fifty-five million, five hundred twenty thousand, five hundred fifty-seven".