1521221966 has 16 divisors (see below), whose sum is σ = 2620287360. Its totient is φ = 655071480.

The previous prime is 1521221963. The next prime is 1521221969. The reversal of 1521221966 is 6691221251.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1521221963) and next prime (1521221969).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1521221963) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1819226 + ... + 1820061.

It is an arithmetic number, because the mean of its divisors is an integer number (163767960).

Almost surely, 2^1521221966 is an apocalyptic number.

1521221966 is a deficient number, since it is larger than the sum of its proper divisors (1099065394).

1521221966 is a wasteful number, since it uses less digits than its factorization.

1521221966 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3639319.

The product of its digits is 12960, while the sum is 35.

The square root of 1521221966 is about 39002.8456141344. The cubic root of 1521221966 is about 1150.0874453984.

The spelling of 1521221966 in words is "one billion, five hundred twenty-one million, two hundred twenty-one thousand, nine hundred sixty-six".