21061417393 has 2 divisors, whose sum is σ = 21061417394. Its totient is φ = 21061417392.

The previous prime is 21061417379. The next prime is 21061417409. The reversal of 21061417393 is 39371416012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18701109504 + 2360307889 = 136752^2 + 48583^2 .

It is a cyclic number.

It is not a de Polignac number, because 21061417393 - 2¹⁷ = 21061286321 is a prime.

It is not a weakly prime, because it can be changed into another prime (21061418393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10530708696 + 10530708697.

It is an arithmetic number, because the mean of its divisors is an integer number (10530708697).

Almost surely, 2^21061417393 is an apocalyptic number.

It is an amenable number.

21061417393 is a deficient number, since it is larger than the sum of its proper divisors (1).

21061417393 is an equidigital number, since it uses as much as digits as its factorization.

21061417393 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27216, while the sum is 37.

The spelling of 21061417393 in words is "twenty-one billion, sixty-one million, four hundred seventeen thousand, three hundred ninety-three".