2153975975449 has 9 divisors (see below), whose sum is σ = 2157673430367. Its totient is φ = 2150284853304.

The previous prime is 2153975975399. The next prime is 2153975975453. The reversal of 2153975975449 is 9445795793512.

The square root of 2153975975449 is 1467643.

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., 431760697225 + 1722215278224 = 657085^2 + 1312332^2 .

It is not a de Polignac number, because 2153975975449 - 2¹³ = 2153975967257 is a prime.

It is a super-2 number, since 2×2153975975449² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2153975915449) 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, 1348763119 + ... + 1348764715.

It is an arithmetic number, because the mean of its divisors is an integer number (239741492263).

Almost surely, 2^{2153975975449} is an apocalyptic number.

2153975975449 is the 1467643-rd square number.

2153975975449 is the 733822-nd centered octagonal number.

It is an amenable number.

2153975975449 is a deficient number, since it is larger than the sum of its proper divisors (3697454918).

2153975975449 is an frugal number, since it uses more digits than its factorization.

2153975975449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5032 (or 2516 counting only the distinct ones).

The product of its digits is 428652000, while the sum is 70.

The spelling of 2153975975449 in words is "two trillion, one hundred fifty-three billion, nine hundred seventy-five million, nine hundred seventy-five thousand, four hundred forty-nine".