21506730621122 has 4 divisors (see below), whose sum is σ = 32260095931686. Its totient is φ = 10753365310560.

The previous prime is 21506730621043. The next prime is 21506730621161. The reversal of 21506730621122 is 22112603760512.

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., 11378876281081 + 10127854340041 = 3373259^2 + 3182429^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5376682655279 + ... + 5376682655282.

Almost surely, 2^{21506730621122} is an apocalyptic number.

21506730621122 is a deficient number, since it is larger than the sum of its proper divisors (10753365310564).

21506730621122 is a wasteful number, since it uses less digits than its factorization.

21506730621122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10753365310563.

The product of its (nonzero) digits is 60480, while the sum is 38.

The spelling of 21506730621122 in words is "twenty-one trillion, five hundred six billion, seven hundred thirty million, six hundred twenty-one thousand, one hundred twenty-two".