55551661636 has 27 divisors (see below), whose sum is σ = 97885701277. Its totient is φ = 27585625760.

The previous prime is 55551661621. The next prime is 55551661637. The reversal of 55551661636 is 63616615555.

The square root of 55551661636 is 235694.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 1608812100 + 53942849536 = 40110^2 + 232256^2 .

It is a super-2 number, since 2×55551661636² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

Its product of digits (2430000) is a multiple of the sum of its prime divisors (810).

It is a self number, because there is not a number n which added to its sum of digits gives 55551661636.

It is not an unprimeable number, because it can be changed into a prime (55551661637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 90034800 + ... + 90035416.

Almost surely, 2^55551661636 is an apocalyptic number.

55551661636 is the 235694-th square number.

It is an amenable number.

55551661636 is a deficient number, since it is larger than the sum of its proper divisors (42334039641).

55551661636 is an frugal number, since it uses more digits than its factorization.

55551661636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1620 (or 810 counting only the distinct ones).

The product of its digits is 2430000, while the sum is 49.

Multiplying 55551661636 by its sum of digits (49), we get a square (2722031420164 = 1649858²).

The spelling of 55551661636 in words is "fifty-five billion, five hundred fifty-one million, six hundred sixty-one thousand, six hundred thirty-six".