1551551666 has 32 divisors (see below), whose sum is σ = 2828703360. Its totient is φ = 623448576.

The previous prime is 1551551633. The next prime is 1551551669. The reversal of 1551551666 is 6661551551.

It is not an unprimeable number, because it can be changed into a prime (1551551669) 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 15 ways as a sum of consecutive naturals, for example, 4265 + ... + 55868.

It is an arithmetic number, because the mean of its divisors is an integer number (88396980).

Almost surely, 2^1551551666 is an apocalyptic number.

1551551666 is a deficient number, since it is larger than the sum of its proper divisors (1277151694).

1551551666 is a wasteful number, since it uses less digits than its factorization.

1551551666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60258.

The product of its digits is 135000, while the sum is 41.

The square root of 1551551666 is about 39389.7406185926. The cubic root of 1551551666 is about 1157.6805779471.

The spelling of 1551551666 in words is "one billion, five hundred fifty-one million, five hundred fifty-one thousand, six hundred sixty-six".