21162025 has 36 divisors (see below), whose sum is σ = 29122020. Its totient is φ = 15232000.

The previous prime is 21162019. The next prime is 21162041. The reversal of 21162025 is 52026112.

It can be written as a sum of positive squares in 18 ways, for example, as 2178576 + 18983449 = 1476^2 + 4357^2 .

It is not a de Polignac number, because 21162025 - 2¹⁷ = 21030953 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21161993 and 21162011.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 209475 + ... + 209575.

It is an arithmetic number, because the mean of its divisors is an integer number (808945).

Almost surely, 2^21162025 is an apocalyptic number.

21162025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21162025 is a deficient number, since it is larger than the sum of its proper divisors (7959995).

21162025 is a wasteful number, since it uses less digits than its factorization.

21162025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174 (or 152 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 21162025 is about 4600.2201034298. The cubic root of 21162025 is about 276.6001477152.

Adding to 21162025 its reverse (52026112), we get a palindrome (73188137).

It can be divided in two parts, 2116 and 2025, that multiplied together give a square (4284900 = 2070²).

The spelling of 21162025 in words is "twenty-one million, one hundred sixty-two thousand, twenty-five".