21525354231 has 4 divisors (see below), whose sum is σ = 28700472312. Its totient is φ = 14350236152.

The previous prime is 21525354209. The next prime is 21525354259. The reversal of 21525354231 is 13245352512.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21525354231 - 2⁶ = 21525354167 is a prime.

It is a super-2 number, since 2×21525354231² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21525354192 and 21525354201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21525354131) 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 3 ways as a sum of consecutive naturals, for example, 3587559036 + ... + 3587559041.

It is an arithmetic number, because the mean of its divisors is an integer number (7175118078).

Almost surely, 2^21525354231 is an apocalyptic number.

21525354231 is a deficient number, since it is larger than the sum of its proper divisors (7175118081).

21525354231 is an equidigital number, since it uses as much as digits as its factorization.

21525354231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7175118080.

The product of its digits is 36000, while the sum is 33.

The spelling of 21525354231 in words is "twenty-one billion, five hundred twenty-five million, three hundred fifty-four thousand, two hundred thirty-one".