21250567 has 6 divisors (see below), whose sum is σ = 23011152. Its totient is φ = 19615752.

The previous prime is 21250553. The next prime is 21250571. The reversal of 21250567 is 76505212.

It is not a de Polignac number, because 21250567 - 2¹¹ = 21248519 is a prime.

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

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21250517) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 62703 + ... + 63040.

It is an arithmetic number, because the mean of its divisors is an integer number (3835192).

Almost surely, 2^21250567 is an apocalyptic number.

21250567 is a deficient number, since it is larger than the sum of its proper divisors (1760585).

21250567 is a wasteful number, since it uses less digits than its factorization.

21250567 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125769 (or 125756 counting only the distinct ones).

The product of its (nonzero) digits is 4200, while the sum is 28.

The square root of 21250567 is about 4609.8337280210. The cubic root of 21250567 is about 276.9853763344.

Adding to 21250567 its reverse (76505212), we get a palindrome (97755779).

The spelling of 21250567 in words is "twenty-one million, two hundred fifty thousand, five hundred sixty-seven".