21474517 has 2 divisors, whose sum is σ = 21474518. Its totient is φ = 21474516.

The previous prime is 21474511. The next prime is 21474521. The reversal of 21474517 is 71547412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11015761 + 10458756 = 3319^2 + 3234^2 .

It is a cyclic number.

It is not a de Polignac number, because 21474517 - 2¹⁹ = 20950229 is a prime.

It is a super-2 number, since 2×21474517² = 922309760766578, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21474511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10737258 + 10737259.

It is an arithmetic number, because the mean of its divisors is an integer number (10737259).

Almost surely, 2^21474517 is an apocalyptic number.

It is an amenable number.

21474517 is a deficient number, since it is larger than the sum of its proper divisors (1).

21474517 is an equidigital number, since it uses as much as digits as its factorization.

21474517 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7840, while the sum is 31.

The square root of 21474517 is about 4634.0605304635. The cubic root of 21474517 is about 277.9549855518.

The spelling of 21474517 in words is "twenty-one million, four hundred seventy-four thousand, five hundred seventeen".