55617661 has 4 divisors (see below), whose sum is σ = 60673824. Its totient is φ = 50561500.

The previous prime is 55617649. The next prime is 55617671. The reversal of 55617661 is 16671655.

55617661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 not a de Polignac number, because 55617661 - 2⁵ = 55617629 is a prime.

It is a super-2 number, since 2×55617661² = 6186648430221842, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 55617661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (55617671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2528065 + ... + 2528086.

It is an arithmetic number, because the mean of its divisors is an integer number (15168456).

Almost surely, 2^55617661 is an apocalyptic number.

It is an amenable number.

55617661 is a deficient number, since it is larger than the sum of its proper divisors (5056163).

55617661 is a wasteful number, since it uses less digits than its factorization.

55617661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5056162.

The product of its digits is 37800, while the sum is 37.

The square root of 55617661 is about 7457.7249211807. The cubic root of 55617661 is about 381.7135472078.

It can be divided in two parts, 55 and 617661, that added together give a palindrome (617716).

The spelling of 55617661 in words is "fifty-five million, six hundred seventeen thousand, six hundred sixty-one".