6661500554 has 4 divisors (see below), whose sum is σ = 9992250834. Its totient is φ = 3330750276.

The previous prime is 6661500553. The next prime is 6661500563. The reversal of 6661500554 is 4550051666.

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., 5256975025 + 1404525529 = 72505^2 + 37477^2 .

It is not an unprimeable number, because it can be changed into a prime (6661500553) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1665375137 + ... + 1665375140.

Almost surely, 2^6661500554 is an apocalyptic number.

6661500554 is a deficient number, since it is larger than the sum of its proper divisors (3330750280).

6661500554 is a wasteful number, since it uses less digits than its factorization.

6661500554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3330750279.

The product of its (nonzero) digits is 108000, while the sum is 38.

The square root of 6661500554 is about 81618.0161116404. The cubic root of 6661500554 is about 1881.5857823179.

The spelling of 6661500554 in words is "six billion, six hundred sixty-one million, five hundred thousand, five hundred fifty-four".