21251103523 has 8 divisors (see below), whose sum is σ = 22887082400. Its totient is φ = 19615307328.

The previous prime is 21251103493. The next prime is 21251103547. The reversal of 21251103523 is 32530115212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21251103523 - 2²¹ = 21249006371 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21251103563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 284263 + ... + 351151.

It is an arithmetic number, because the mean of its divisors is an integer number (2860885300).

Almost surely, 2^21251103523 is an apocalyptic number.

21251103523 is a deficient number, since it is larger than the sum of its proper divisors (1635978877).

21251103523 is a wasteful number, since it uses less digits than its factorization.

21251103523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91341.

The product of its (nonzero) digits is 1800, while the sum is 25.

Adding to 21251103523 its reverse (32530115212), we get a palindrome (53781218735).

The spelling of 21251103523 in words is "twenty-one billion, two hundred fifty-one million, one hundred three thousand, five hundred twenty-three".