21250877 has 2 divisors, whose sum is σ = 21250878. Its totient is φ = 21250876.

The previous prime is 21250849. The next prime is 21250961. The reversal of 21250877 is 77805212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19545241 + 1705636 = 4421^2 + 1306^2 .

It is a cyclic number.

It is not a de Polignac number, because 21250877 - 2⁶ = 21250813 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21250807) 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, 10625438 + 10625439.

It is an arithmetic number, because the mean of its divisors is an integer number (10625439).

Almost surely, 2^21250877 is an apocalyptic number.

It is an amenable number.

21250877 is a deficient number, since it is larger than the sum of its proper divisors (1).

21250877 is an equidigital number, since it uses as much as digits as its factorization.

21250877 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7840, while the sum is 32.

The square root of 21250877 is about 4609.8673516708. The cubic root of 21250877 is about 276.9867232012.

The spelling of 21250877 in words is "twenty-one million, two hundred fifty thousand, eight hundred seventy-seven".