21150523 has 2 divisors, whose sum is σ = 21150524. Its totient is φ = 21150522.

The previous prime is 21150491. The next prime is 21150607. The reversal of 21150523 is 32505112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21150523 - 2⁵ = 21150491 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21150523.

It is not a weakly prime, because it can be changed into another prime (21150223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10575261 + 10575262.

It is an arithmetic number, because the mean of its divisors is an integer number (10575262).

Almost surely, 2^21150523 is an apocalyptic number.

21150523 is a deficient number, since it is larger than the sum of its proper divisors (1).

21150523 is an equidigital number, since it uses as much as digits as its factorization.

21150523 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 300, while the sum is 19.

The square root of 21150523 is about 4598.9697759390. The cubic root of 21150523 is about 276.5500259921.

Adding to 21150523 its reverse (32505112), we get a palindrome (53655635).

It can be divided in two parts, 21 and 150523, that added together give a square (150544 = 388²).

The spelling of 21150523 in words is "twenty-one million, one hundred fifty thousand, five hundred twenty-three".