21151025 has 12 divisors (see below), whose sum is σ = 29974272. Its totient is φ = 14503440.

The previous prime is 21150991. The next prime is 21151027. The reversal of 21151025 is 52015112.

It is not a de Polignac number, because 21151025 - 2¹⁰ = 21150001 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21150994 and 21151012.

It is not an unprimeable number, because it can be changed into a prime (21151027) 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, 60257 + ... + 60606.

It is an arithmetic number, because the mean of its divisors is an integer number (2497856).

Almost surely, 2^21151025 is an apocalyptic number.

21151025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21151025 is a deficient number, since it is larger than the sum of its proper divisors (8823247).

21151025 is a wasteful number, since it uses less digits than its factorization.

21151025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120880 (or 120875 counting only the distinct ones).

The product of its (nonzero) digits is 100, while the sum is 17.

The square root of 21151025 is about 4599.0243530558. The cubic root of 21151025 is about 276.5522139130.

Adding to 21151025 its reverse (52015112), we get a palindrome (73166137).

The spelling of 21151025 in words is "twenty-one million, one hundred fifty-one thousand, twenty-five".