12221601506 has 4 divisors (see below), whose sum is σ = 18332402262. Its totient is φ = 6110800752.

The previous prime is 12221601499. The next prime is 12221601577. The reversal of 12221601506 is 60510612221.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 11175661225 + 1045940281 = 105715^2 + 32341^2 .

It is a super-2 number, since 2×12221601506² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3055400375 + ... + 3055400378.

Almost surely, 2^12221601506 is an apocalyptic number.

12221601506 is a deficient number, since it is larger than the sum of its proper divisors (6110800756).

12221601506 is an equidigital number, since it uses as much as digits as its factorization.

12221601506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6110800755.

The product of its (nonzero) digits is 1440, while the sum is 26.

The spelling of 12221601506 in words is "twelve billion, two hundred twenty-one million, six hundred one thousand, five hundred six".