21162650638457 has 2 divisors, whose sum is σ = 21162650638458. Its totient is φ = 21162650638456.

The previous prime is 21162650638411. The next prime is 21162650638463. The reversal of 21162650638457 is 75483605626112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21131452834816 + 31197803641 = 4596896^2 + 176629^2 .

It is a cyclic number.

It is not a de Polignac number, because 21162650638457 - 2⁸ = 21162650638201 is a prime.

It is a super-4 number, since 4×21162650638457⁴ (a number of 54 digits) contains 4444 as substring. Note that it is a super-d number also for d = 3.

It is not a weakly prime, because it can be changed into another prime (21162650638477) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10581325319228 + 10581325319229.

It is an arithmetic number, because the mean of its divisors is an integer number (10581325319229).

Almost surely, 2^{21162650638457} is an apocalyptic number.

It is an amenable number.

21162650638457 is a deficient number, since it is larger than the sum of its proper divisors (1).

21162650638457 is an equidigital number, since it uses as much as digits as its factorization.

21162650638457 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14515200, while the sum is 56.

The spelling of 21162650638457 in words is "twenty-one trillion, one hundred sixty-two billion, six hundred fifty million, six hundred thirty-eight thousand, four hundred fifty-seven".