21475689 has 16 divisors (see below), whose sum is σ = 29798400. Its totient is φ = 13741056.

The previous prime is 21475687. The next prime is 21475697. The reversal of 21475689 is 98657412.

It is not a de Polignac number, because 21475689 - 2¹ = 21475687 is a prime.

It is a super-2 number, since 2×21475689² = 922410436049442, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21475689.

It is not an unprimeable number, because it can be changed into a prime (21475687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16152 + ... + 17430.

It is an arithmetic number, because the mean of its divisors is an integer number (1862400).

Almost surely, 2^21475689 is an apocalyptic number.

21475689 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

21475689 is a deficient number, since it is larger than the sum of its proper divisors (8322711).

21475689 is a wasteful number, since it uses less digits than its factorization.

21475689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1504.

The product of its digits is 120960, while the sum is 42.

The square root of 21475689 is about 4634.1869837114. The cubic root of 21475689 is about 277.9600420461.

The spelling of 21475689 in words is "twenty-one million, four hundred seventy-five thousand, six hundred eighty-nine".