21496649 has 2 divisors, whose sum is σ = 21496650. Its totient is φ = 21496648.

The previous prime is 21496637. The next prime is 21496661. The reversal of 21496649 is 94669412.

It is a balanced prime because it is at equal distance from previous prime (21496637) and next prime (21496661).

It can be written as a sum of positive squares in only one way, i.e., 15405625 + 6091024 = 3925^2 + 2468^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21496649 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21496679) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10748324 + 10748325.

It is an arithmetic number, because the mean of its divisors is an integer number (10748325).

Almost surely, 2^21496649 is an apocalyptic number.

It is an amenable number.

21496649 is a deficient number, since it is larger than the sum of its proper divisors (1).

21496649 is an equidigital number, since it uses as much as digits as its factorization.

21496649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 93312, while the sum is 41.

The square root of 21496649 is about 4636.4478860438. The cubic root of 21496649 is about 278.0504411345.

The spelling of 21496649 in words is "twenty-one million, four hundred ninety-six thousand, six hundred forty-nine".