21400412417 has 2 divisors, whose sum is σ = 21400412418. Its totient is φ = 21400412416.

The previous prime is 21400412377. The next prime is 21400412471. The reversal of 21400412417 is 71421400412.

Together with next prime (21400412471) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15606005776 + 5794406641 = 124924^2 + 76121^2 .

It is a cyclic number.

It is not a de Polignac number, because 21400412417 - 2¹² = 21400408321 is a prime.

It is not a weakly prime, because it can be changed into another prime (21400412477) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10700206208 + 10700206209.

It is an arithmetic number, because the mean of its divisors is an integer number (10700206209).

Almost surely, 2^21400412417 is an apocalyptic number.

It is an amenable number.

21400412417 is a deficient number, since it is larger than the sum of its proper divisors (1).

21400412417 is an equidigital number, since it uses as much as digits as its factorization.

21400412417 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1792, while the sum is 26.

Adding to 21400412417 its reverse (71421400412), we get a palindrome (92821812829).

The spelling of 21400412417 in words is "twenty-one billion, four hundred million, four hundred twelve thousand, four hundred seventeen".