1521666164 has 6 divisors (see below), whose sum is σ = 2662915794. Its totient is φ = 760833080.

The previous prime is 1521666151. The next prime is 1521666173. The reversal of 1521666164 is 4616661251.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 1108357264 + 413308900 = 33292^2 + 20330^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 190208267 + ... + 190208274.

It is an arithmetic number, because the mean of its divisors is an integer number (443819299).

Almost surely, 2^1521666164 is an apocalyptic number.

It is an amenable number.

1521666164 is a deficient number, since it is larger than the sum of its proper divisors (1141249630).

1521666164 is a wasteful number, since it uses less digits than its factorization.

1521666164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 380416545 (or 380416543 counting only the distinct ones).

The product of its digits is 51840, while the sum is 38.

The square root of 1521666164 is about 39008.5396291633. The cubic root of 1521666164 is about 1150.1993766480.

The spelling of 1521666164 in words is "one billion, five hundred twenty-one million, six hundred sixty-six thousand, one hundred sixty-four".