55666890 has 24 divisors (see below), whose sum is σ = 144734148. Its totient is φ = 14844480.

The previous prime is 55666841. The next prime is 55666901. The reversal of 55666890 is 9866655.

It can be written as a sum of positive squares in 2 ways, for example, as 50509449 + 5157441 = 7107^2 + 2271^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 309171 + ... + 309350.

Almost surely, 2^55666890 is an apocalyptic number.

55666890 is an abundant number, since it is smaller than the sum of its proper divisors (89067258).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

55666890 is a wasteful number, since it uses less digits than its factorization.

55666890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 618534 (or 618531 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 45.

The square root of 55666890 is about 7461.0247285477. The cubic root of 55666890 is about 381.8261363525.

The spelling of 55666890 in words is "fifty-five million, six hundred sixty-six thousand, eight hundred ninety".