21196579172 has 24 divisors (see below), whose sum is σ = 37380123480. Its totient is φ = 10516608000.

The previous prime is 21196579147. The next prime is 21196579207. The reversal of 21196579172 is 27197569112.

It can be written as a sum of positive squares in 4 ways, for example, as 5508014656 + 15688564516 = 74216^2 + 125254^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21196579172.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 1638104 + ... + 1650992.

It is an arithmetic number, because the mean of its divisors is an integer number (1557505145).

Almost surely, 2^21196579172 is an apocalyptic number.

It is an amenable number.

21196579172 is a deficient number, since it is larger than the sum of its proper divisors (16183544308).

21196579172 is a wasteful number, since it uses less digits than its factorization.

21196579172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16031 (or 16029 counting only the distinct ones).

The product of its digits is 476280, while the sum is 50.

The spelling of 21196579172 in words is "twenty-one billion, one hundred ninety-six million, five hundred seventy-nine thousand, one hundred seventy-two".