21529425 has 12 divisors (see below), whose sum is σ = 35595440. Its totient is φ = 11482320.

The previous prime is 21529423. The next prime is 21529427. The reversal of 21529425 is 52492512.

It is an interprime number because it is at equal distance from previous prime (21529423) and next prime (21529427).

It is not a de Polignac number, because 21529425 - 2¹ = 21529423 is a prime.

It is a super-2 number, since 2×21529425² = 927032281661250, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21529392 and 21529401.

It is not an unprimeable number, because it can be changed into a prime (21529423) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 143455 + ... + 143604.

Almost surely, 2^21529425 is an apocalyptic number.

21529425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21529425 is a deficient number, since it is larger than the sum of its proper divisors (14066015).

21529425 is a wasteful number, since it uses less digits than its factorization.

21529425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 287072 (or 287067 counting only the distinct ones).

The product of its digits is 7200, while the sum is 30.

The square root of 21529425 is about 4639.9811422031. The cubic root of 21529425 is about 278.1916841324.

The spelling of 21529425 in words is "twenty-one million, five hundred twenty-nine thousand, four hundred twenty-five".