21083773 has 2 divisors, whose sum is σ = 21083774. Its totient is φ = 21083772.

The previous prime is 21083719. The next prime is 21083779. The reversal of 21083773 is 37738012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16426809 + 4656964 = 4053^2 + 2158^2 .

It is a cyclic number.

It is not a de Polignac number, because 21083773 - 2²¹ = 18986621 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21083779) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10541886 + 10541887.

It is an arithmetic number, because the mean of its divisors is an integer number (10541887).

Almost surely, 2^21083773 is an apocalyptic number.

It is an amenable number.

21083773 is a deficient number, since it is larger than the sum of its proper divisors (1).

21083773 is an equidigital number, since it uses as much as digits as its factorization.

21083773 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7056, while the sum is 31.

The square root of 21083773 is about 4591.7069810692. The cubic root of 21083773 is about 276.2587933566.

The spelling of 21083773 in words is "twenty-one million, eighty-three thousand, seven hundred seventy-three".