55507666 has 4 divisors (see below), whose sum is σ = 83261502. Its totient is φ = 27753832.

The previous prime is 55507663. The next prime is 55507679. The reversal of 55507666 is 66670555.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 28933641 + 26574025 = 5379^2 + 5155^2 .

It is a super-2 number, since 2×55507666² = 6162201969535112, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (55507663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13876915 + ... + 13876918.

Almost surely, 2^55507666 is an apocalyptic number.

55507666 is a deficient number, since it is larger than the sum of its proper divisors (27753836).

55507666 is a wasteful number, since it uses less digits than its factorization.

55507666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27753835.

The product of its (nonzero) digits is 189000, while the sum is 40.

The square root of 55507666 is about 7450.3467033421. The cubic root of 55507666 is about 381.4617429531.

The spelling of 55507666 in words is "fifty-five million, five hundred seven thousand, six hundred sixty-six".