20893835209 has 9 divisors (see below), whose sum is σ = 22626720423. Its totient is φ = 19284882552.

The previous prime is 20893835201. The next prime is 20893835231. The reversal of 20893835209 is 90253839802.

The square root of 20893835209 is 144547.

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., 3090804025 + 17803031184 = 55595^2 + 133428^2 .

It is not a de Polignac number, because 20893835209 - 2³ = 20893835201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20893835201) 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, 1873552 + ... + 1884670.

It is an arithmetic number, because the mean of its divisors is an integer number (2514080047).

Almost surely, 2^20893835209 is an apocalyptic number.

20893835209 is the 144547-th square number.

20893835209 is the 72274-th centered octagonal number.

It is an amenable number.

20893835209 is a deficient number, since it is larger than the sum of its proper divisors (1732885214).

20893835209 is an frugal number, since it uses more digits than its factorization.

20893835209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22264 (or 11132 counting only the distinct ones).

The product of its (nonzero) digits is 933120, while the sum is 49.

Multiplying 20893835209 by its sum of digits (49), we get a square (1023797925241 = 1011829²).

The spelling of 20893835209 in words is "twenty billion, eight hundred ninety-three million, eight hundred thirty-five thousand, two hundred nine".