21250693 has 2 divisors, whose sum is σ = 21250694. Its totient is φ = 21250692.

The previous prime is 21250687. The next prime is 21250709. The reversal of 21250693 is 39605212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21224449 + 26244 = 4607^2 + 162^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21250693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21250393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10625346 + 10625347.

It is an arithmetic number, because the mean of its divisors is an integer number (10625347).

Almost surely, 2^21250693 is an apocalyptic number.

It is an amenable number.

21250693 is a deficient number, since it is larger than the sum of its proper divisors (1).

21250693 is an equidigital number, since it uses as much as digits as its factorization.

21250693 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3240, while the sum is 28.

The square root of 21250693 is about 4609.8473944373. The cubic root of 21250693 is about 276.9859237722.

Adding to 21250693 its product of nonzero digits (3240), we get a cube (21253933 = 277³).

It can be divided in two parts, 212 and 50693, that added together give a palindrome (50905).

The spelling of 21250693 in words is "twenty-one million, two hundred fifty thousand, six hundred ninety-three".