21610949 has 2 divisors, whose sum is σ = 21610950. Its totient is φ = 21610948.

The previous prime is 21610943. The next prime is 21610957. The reversal of 21610949 is 94901612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20994724 + 616225 = 4582^2 + 785^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21610949 is a prime.

It is a Chen prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21610943) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10805474 + 10805475.

It is an arithmetic number, because the mean of its divisors is an integer number (10805475).

Almost surely, 2^21610949 is an apocalyptic number.

It is an amenable number.

21610949 is a deficient number, since it is larger than the sum of its proper divisors (1).

21610949 is an equidigital number, since it uses as much as digits as its factorization.

21610949 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 21610949 is about 4648.7577910663. The cubic root of 21610949 is about 278.5423783238.

The spelling of 21610949 in words is "twenty-one million, six hundred ten thousand, nine hundred forty-nine".