21170268061 has 4 divisors (see below), whose sum is σ = 21186295324. Its totient is φ = 21154240800.

The previous prime is 21170268043. The next prime is 21170268071. The reversal of 21170268061 is 16086207112.

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

It can be written as a sum of positive squares in 2 ways, for example, as 13828348836 + 7341919225 = 117594^2 + 85685^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21170268061 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21170268071) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8011650 + ... + 8014291.

It is an arithmetic number, because the mean of its divisors is an integer number (5296573831).

Almost surely, 2^21170268061 is an apocalyptic number.

21170268061 is the 84005-th hex number.

It is an amenable number.

21170268061 is a deficient number, since it is larger than the sum of its proper divisors (16027263).

21170268061 is a wasteful number, since it uses less digits than its factorization.

21170268061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16027262.

The product of its (nonzero) digits is 8064, while the sum is 34.

The spelling of 21170268061 in words is "twenty-one billion, one hundred seventy million, two hundred sixty-eight thousand, sixty-one".