21489135 has 16 divisors (see below), whose sum is σ = 34636896. Its totient is φ = 11376128.

The previous prime is 21489101. The next prime is 21489137. The reversal of 21489135 is 53198412.

It is a cyclic number.

It is not a de Polignac number, because 21489135 - 2⁷ = 21489007 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21489096 and 21489105.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21489137) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3174 + ... + 7283.

It is an arithmetic number, because the mean of its divisors is an integer number (2164806).

Almost surely, 2^21489135 is an apocalyptic number.

21489135 is a deficient number, since it is larger than the sum of its proper divisors (13147761).

21489135 is a wasteful number, since it uses less digits than its factorization.

21489135 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10602.

The product of its digits is 8640, while the sum is 33.

The square root of 21489135 is about 4635.6374966125. The cubic root of 21489135 is about 278.0180405110.

It can be divided in two parts, 2148 and 9135, that multiplied together give a triangular number (19621980 = T₆₂₆₄).

The spelling of 21489135 in words is "twenty-one million, four hundred eighty-nine thousand, one hundred thirty-five".