21425253 has 8 divisors (see below), whose sum is σ = 30247488. Its totient is φ = 13443264.

The previous prime is 21425251. The next prime is 21425269. The reversal of 21425253 is 35252412.

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

It is not a de Polignac number, because 21425253 - 2¹ = 21425251 is a prime.

It is a super-2 number, since 2×21425253² = 918082932228018, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21425251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 210001 + ... + 210102.

It is an arithmetic number, because the mean of its divisors is an integer number (3780936).

Almost surely, 2^21425253 is an apocalyptic number.

It is an amenable number.

21425253 is a deficient number, since it is larger than the sum of its proper divisors (8822235).

21425253 is a wasteful number, since it uses less digits than its factorization.

21425253 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 420123.

The product of its digits is 2400, while the sum is 24.

The square root of 21425253 is about 4628.7420537334. The cubic root of 21425253 is about 277.7422736074.

Adding to 21425253 its reverse (35252412), we get a palindrome (56677665).

The spelling of 21425253 in words is "twenty-one million, four hundred twenty-five thousand, two hundred fifty-three".