21250241360661 has 16 divisors (see below), whose sum is σ = 28499065482240. Its totient is φ = 14084211295680.

The previous prime is 21250241360639. The next prime is 21250241360671. The reversal of 21250241360661 is 16606314205212.

It is not a de Polignac number, because 21250241360661 - 2⁷ = 21250241360533 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21250241360671) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10153890 + ... + 12066563.

It is an arithmetic number, because the mean of its divisors is an integer number (1781191592640).

Almost surely, 2^{21250241360661} is an apocalyptic number.

It is an amenable number.

21250241360661 is a deficient number, since it is larger than the sum of its proper divisors (7248824121579).

21250241360661 is a wasteful number, since it uses less digits than its factorization.

21250241360661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22222316.

The product of its (nonzero) digits is 103680, while the sum is 39.

Adding to 21250241360661 its reverse (16606314205212), we get a palindrome (37856555565873).

The spelling of 21250241360661 in words is "twenty-one trillion, two hundred fifty billion, two hundred forty-one million, three hundred sixty thousand, six hundred sixty-one".