1521551979 has 16 divisors (see below), whose sum is σ = 2256107040. Its totient is φ = 1013487840.

The previous prime is 1521551957. The next prime is 1521551987. The reversal of 1521551979 is 9791551251.

It is a happy number.

1521551979 is a `hidden beast` number, since 1 + 5 + 2 + 1 + 551 + 97 + 9 = 666.

It is not a de Polignac number, because 1521551979 - 2¹⁵ = 1521519211 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1521551909) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8029 + ... + 55745.

It is an arithmetic number, because the mean of its divisors is an integer number (141006690).

Almost surely, 2^1521551979 is an apocalyptic number.

1521551979 is a deficient number, since it is larger than the sum of its proper divisors (734555061).

1521551979 is a wasteful number, since it uses less digits than its factorization.

1521551979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48907 (or 48901 counting only the distinct ones).

The product of its digits is 141750, while the sum is 45.

The square root of 1521551979 is about 39007.0760119238. The cubic root of 1521551979 is about 1150.1706058168.

The spelling of 1521551979 in words is "one billion, five hundred twenty-one million, five hundred fifty-one thousand, nine hundred seventy-nine".