21401617 has 2 divisors, whose sum is σ = 21401618. Its totient is φ = 21401616.

The previous prime is 21401593. The next prime is 21401641. The reversal of 21401617 is 71610412.

It is a balanced prime because it is at equal distance from previous prime (21401593) and next prime (21401641).

It can be written as a sum of positive squares in only one way, i.e., 18870336 + 2531281 = 4344^2 + 1591^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21401617 is a prime.

It is not a weakly prime, because it can be changed into another prime (21401647) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10700808 + 10700809.

It is an arithmetic number, because the mean of its divisors is an integer number (10700809).

Almost surely, 2^21401617 is an apocalyptic number.

It is an amenable number.

21401617 is a deficient number, since it is larger than the sum of its proper divisors (1).

21401617 is an equidigital number, since it uses as much as digits as its factorization.

21401617 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 336, while the sum is 22.

The square root of 21401617 is about 4626.1881717025. The cubic root of 21401617 is about 277.6401024002.

The spelling of 21401617 in words is "twenty-one million, four hundred one thousand, six hundred seventeen".