21058943689 has 9 divisors (see below), whose sum is σ = 24498320301. Its totient is φ = 18049652460.

The previous prime is 21058943651. The next prime is 21058943723. The reversal of 21058943689 is 98634985012.

The square root of 21058943689 is 145117.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 21058943689 - 2¹³ = 21058935497 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21058943489) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1005454 + ... + 1026184.

It is an arithmetic number, because the mean of its divisors is an integer number (2722035589).

Almost surely, 2^21058943689 is an apocalyptic number.

21058943689 is the 145117-th square number.

21058943689 is the 72559-th centered octagonal number.

It is an amenable number.

21058943689 is a deficient number, since it is larger than the sum of its proper divisors (3439376612).

21058943689 is an frugal number, since it uses more digits than its factorization.

21058943689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41476 (or 20738 counting only the distinct ones).

The product of its (nonzero) digits is 3732480, while the sum is 55.

The spelling of 21058943689 in words is "twenty-one billion, fifty-eight million, nine hundred forty-three thousand, six hundred eighty-nine".