21074657 has 2 divisors, whose sum is σ = 21074658. Its totient is φ = 21074656.

The previous prime is 21074639. The next prime is 21074681. The reversal of 21074657 is 75647012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15673681 + 5400976 = 3959^2 + 2324^2 .

It is a cyclic number.

It is not a de Polignac number, because 21074657 - 2¹⁴ = 21058273 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21074057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10537328 + 10537329.

It is an arithmetic number, because the mean of its divisors is an integer number (10537329).

Almost surely, 2^21074657 is an apocalyptic number.

It is an amenable number.

21074657 is a deficient number, since it is larger than the sum of its proper divisors (1).

21074657 is an equidigital number, since it uses as much as digits as its factorization.

21074657 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11760, while the sum is 32.

The square root of 21074657 is about 4590.7142145858. The cubic root of 21074657 is about 276.2189722391.

The spelling of 21074657 in words is "twenty-one million, seventy-four thousand, six hundred fifty-seven".