21770893 has 2 divisors, whose sum is σ = 21770894. Its totient is φ = 21770892.

The previous prime is 21770873. The next prime is 21770927. The reversal of 21770893 is 39807712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21557449 + 213444 = 4643^2 + 462^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21770893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21770803) 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, 10885446 + 10885447.

It is an arithmetic number, because the mean of its divisors is an integer number (10885447).

Almost surely, 2^21770893 is an apocalyptic number.

It is an amenable number.

21770893 is a deficient number, since it is larger than the sum of its proper divisors (1).

21770893 is an equidigital number, since it uses as much as digits as its factorization.

21770893 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21168, while the sum is 37.

The square root of 21770893 is about 4665.9289535954. The cubic root of 21770893 is about 279.2278599153.

The spelling of 21770893 in words is "twenty-one million, seven hundred seventy thousand, eight hundred ninety-three".