21353452425 has 72 divisors (see below), whose sum is σ = 40758891264. Its totient is φ = 10661460480.

The previous prime is 21353452411. The next prime is 21353452427. The reversal of 21353452425 is 52425435312.

21353452425 is a `hidden beast` number, since 21 + 353 + 45 + 242 + 5 = 666.

It is not a de Polignac number, because 21353452425 - 2⁴ = 21353452409 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21353452425.

It is not an unprimeable number, because it can be changed into a prime (21353452427) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 199329 + ... + 287121.

It is an arithmetic number, because the mean of its divisors is an integer number (566095712).

Almost surely, 2^21353452425 is an apocalyptic number.

21353452425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21353452425 is a deficient number, since it is larger than the sum of its proper divisors (19405438839).

21353452425 is a wasteful number, since it uses less digits than its factorization.

21353452425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87879 (or 87871 counting only the distinct ones).

The product of its digits is 144000, while the sum is 36.

Adding to 21353452425 its reverse (52425435312), we get a palindrome (73778887737).

The spelling of 21353452425 in words is "twenty-one billion, three hundred fifty-three million, four hundred fifty-two thousand, four hundred twenty-five".