21417377 has 2 divisors, whose sum is σ = 21417378. Its totient is φ = 21417376.

The previous prime is 21417371. The next prime is 21417437. The reversal of 21417377 is 77371412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20802721 + 614656 = 4561^2 + 784^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21417377 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21417371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10708688 + 10708689.

It is an arithmetic number, because the mean of its divisors is an integer number (10708689).

Almost surely, 2^21417377 is an apocalyptic number.

It is an amenable number.

21417377 is a deficient number, since it is larger than the sum of its proper divisors (1).

21417377 is an equidigital number, since it uses as much as digits as its factorization.

21417377 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8232, while the sum is 32.

The square root of 21417377 is about 4627.8912044256. The cubic root of 21417377 is about 277.7082364170.

Adding to 21417377 its reverse (77371412), we get a palindrome (98788789).

The spelling of 21417377 in words is "twenty-one million, four hundred seventeen thousand, three hundred seventy-seven".