1521306666 has 24 divisors (see below), whose sum is σ = 3595816224. Its totient is φ = 461001960.

The previous prime is 1521306593. The next prime is 1521306673. The reversal of 1521306666 is 6666031251.

It is a self number, because there is not a number n which added to its sum of digits gives 1521306666.

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, 3841486 + ... + 3841881.

It is an arithmetic number, because the mean of its divisors is an integer number (149825676).

Almost surely, 2^1521306666 is an apocalyptic number.

1521306666 is an abundant number, since it is smaller than the sum of its proper divisors (2074509558).

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

1521306666 is a wasteful number, since it uses less digits than its factorization.

1521306666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7683386 (or 7683383 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 36.

The square root of 1521306666 is about 39003.9314172302. The cubic root of 1521306666 is about 1150.1087902122.

The spelling of 1521306666 in words is "one billion, five hundred twenty-one million, three hundred six thousand, six hundred sixty-six".