20409265321 has 27 divisors (see below), whose sum is σ = 22053171159. Its totient is φ = 18885081312.

The previous prime is 20409265313. The next prime is 20409265337. The reversal of 20409265321 is 12356290402.

The square root of 20409265321 is 142861.

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

It can be written as a sum of positive squares in only one way, i.e., 11585293225 + 8823972096 = 107635^2 + 93936^2 .

It is not a de Polignac number, because 20409265321 - 2³ = 20409265313 is a prime.

It is a super-2 number, since 2×20409265321² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20409265361) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 198148156 + ... + 198148258.

It is an arithmetic number, because the mean of its divisors is an integer number (816784117).

Almost surely, 2^20409265321 is an apocalyptic number.

20409265321 is the 142861-st square number.

20409265321 is the 71431-st centered octagonal number.

It is an amenable number.

20409265321 is a deficient number, since it is larger than the sum of its proper divisors (1643905838).

20409265321 is an frugal number, since it uses more digits than its factorization.

20409265321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 390 (or 195 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 34.

The spelling of 20409265321 in words is "twenty billion, four hundred nine million, two hundred sixty-five thousand, three hundred twenty-one".