21151425 has 12 divisors (see below), whose sum is σ = 34970480. Its totient is φ = 11280720.

The previous prime is 21151343. The next prime is 21151433. The reversal of 21151425 is 52415112.

It is not a de Polignac number, because 21151425 - 2¹⁴ = 21135041 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 140935 + ... + 141084.

Almost surely, 2^21151425 is an apocalyptic number.

21151425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21151425 is a deficient number, since it is larger than the sum of its proper divisors (13819055).

21151425 is a wasteful number, since it uses less digits than its factorization.

21151425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 282032 (or 282027 counting only the distinct ones).

The product of its digits is 400, while the sum is 21.

The square root of 21151425 is about 4599.0678403346. The cubic root of 21151425 is about 276.5539572515.

Adding to 21151425 its reverse (52415112), we get a palindrome (73566537).

The spelling of 21151425 in words is "twenty-one million, one hundred fifty-one thousand, four hundred twenty-five".