25221437361721 has 2 divisors, whose sum is σ = 25221437361722. Its totient is φ = 25221437361720.

The previous prime is 25221437361683. The next prime is 25221437361751. The reversal of 25221437361721 is 12716373412252.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 24210680589225 + 1010756772496 = 4920435^2 + 1005364^2 .

It is a cyclic number.

It is not a de Polignac number, because 25221437361721 - 2⁹ = 25221437361209 is a prime.

It is a super-2 number, since 2×25221437361721² (a number of 28 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (25221437361751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12610718680860 + 12610718680861.

It is an arithmetic number, because the mean of its divisors is an integer number (12610718680861).

Almost surely, 2^{25221437361721} is an apocalyptic number.

It is an amenable number.

25221437361721 is a deficient number, since it is larger than the sum of its proper divisors (1).

25221437361721 is an equidigital number, since it uses as much as digits as its factorization.

25221437361721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 846720, while the sum is 46.

The spelling of 25221437361721 in words is "twenty-five trillion, two hundred twenty-one billion, four hundred thirty-seven million, three hundred sixty-one thousand, seven hundred twenty-one".