20161521706 has 4 divisors (see below), whose sum is σ = 30242282562. Its totient is φ = 10080760852.

The previous prime is 20161521703. The next prime is 20161521707. The reversal of 20161521706 is 60712516102.

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., 17605309225 + 2556212481 = 132685^2 + 50559^2 .

It is not an unprimeable number, because it can be changed into a prime (20161521703) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5040380425 + ... + 5040380428.

Almost surely, 2^20161521706 is an apocalyptic number.

20161521706 is a deficient number, since it is larger than the sum of its proper divisors (10080760856).

20161521706 is a wasteful number, since it uses less digits than its factorization.

20161521706 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10080760855.

The product of its (nonzero) digits is 5040, while the sum is 31.

The spelling of 20161521706 in words is "twenty billion, one hundred sixty-one million, five hundred twenty-one thousand, seven hundred six".