21521112523 has 2 divisors, whose sum is σ = 21521112524. Its totient is φ = 21521112522.

The previous prime is 21521112469. The next prime is 21521112563. The reversal of 21521112523 is 32521112512.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21521112523 - 2¹⁷ = 21520981451 is a prime.

It is not a weakly prime, because it can be changed into another prime (21521112563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10760556261 + 10760556262.

It is an arithmetic number, because the mean of its divisors is an integer number (10760556262).

Almost surely, 2^21521112523 is an apocalyptic number.

21521112523 is a deficient number, since it is larger than the sum of its proper divisors (1).

21521112523 is an equidigital number, since it uses as much as digits as its factorization.

21521112523 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1200, while the sum is 25.

The spelling of 21521112523 in words is "twenty-one billion, five hundred twenty-one million, one hundred twelve thousand, five hundred twenty-three".