25721622117217 has 16 divisors (see below), whose sum is σ = 28449687836752. Its totient is φ = 23100662108160.

The previous prime is 25721622117203. The next prime is 25721622117293. The reversal of 25721622117217 is 71271122612752.

It can be written as a sum of positive squares in 8 ways, for example, as 146512107361 + 25575110009856 = 382769^2 + 5057184^2 .

It is not a de Polignac number, because 25721622117217 - 2¹¹ = 25721622115169 is a prime.

It is not an unprimeable number, because it can be changed into a prime (25721622111217) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16212313 + ... + 17728009.

It is an arithmetic number, because the mean of its divisors is an integer number (1778105489797).

Almost surely, 2^{25721622117217} is an apocalyptic number.

It is an amenable number.

25721622117217 is a deficient number, since it is larger than the sum of its proper divisors (2728065719535).

25721622117217 is a wasteful number, since it uses less digits than its factorization.

25721622117217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1551028.

The product of its digits is 329280, while the sum is 46.

Adding to 25721622117217 its reverse (71271122612752), we get a palindrome (96992744729969).

The spelling of 25721622117217 in words is "twenty-five trillion, seven hundred twenty-one billion, six hundred twenty-two million, one hundred seventeen thousand, two hundred seventeen".