20941273521 has 45 divisors (see below), whose sum is σ = 36405862779. Its totient is φ = 11961232416.

The previous prime is 20941273499. The next prime is 20941273541. The reversal of 20941273521 is 12537214902.

The square root of 20941273521 is 144711.

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

20941273521 is a `hidden beast` number, since 2 + 0 + 9 + 4 + 127 + 3 + 521 = 666.

It can be written as a sum of positive squares in only one way, i.e., 9845600625 + 11095672896 = 99225^2 + 105336^2 .

It is not a de Polignac number, because 20941273521 - 2¹¹ = 20941271473 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20941273541) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 9115645 + ... + 9117941.

Almost surely, 2^20941273521 is an apocalyptic number.

20941273521 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

20941273521 is the 144711-st square number.

20941273521 is the 72356-th centered octagonal number.

It is an amenable number.

20941273521 is a deficient number, since it is larger than the sum of its proper divisors (15464589258).

20941273521 is an frugal number, since it uses more digits than its factorization.

20941273521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4620 (or 2307 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

Multiplying 20941273521 by its sum of digits (36), we get a square (753885846756 = 868266²).

The spelling of 20941273521 in words is "twenty billion, nine hundred forty-one million, two hundred seventy-three thousand, five hundred twenty-one".