55615553 has 4 divisors (see below), whose sum is σ = 63560640. Its totient is φ = 47670468.

The previous prime is 55615537. The next prime is 55615559. The reversal of 55615553 is 35551655.

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 not a de Polignac number, because 55615553 - 2⁴ = 55615537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (55615559) 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, 3972533 + ... + 3972546.

It is an arithmetic number, because the mean of its divisors is an integer number (15890160).

Almost surely, 2^55615553 is an apocalyptic number.

It is an amenable number.

55615553 is a deficient number, since it is larger than the sum of its proper divisors (7945087).

55615553 is an equidigital number, since it uses as much as digits as its factorization.

55615553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7945086.

The product of its digits is 56250, while the sum is 35.

The square root of 55615553 is about 7457.5835898768. The cubic root of 55615553 is about 381.7087246250.

It can be divided in two parts, 556 and 15553, that multiplied together give a palindrome (8647468).

The spelling of 55615553 in words is "fifty-five million, six hundred fifteen thousand, five hundred fifty-three".