21475930 has 32 divisors (see below), whose sum is σ = 46780416. Its totient is φ = 6929664.

The previous prime is 21475907. The next prime is 21475939. The reversal of 21475930 is 3957412.

It is a super-2 number, since 2×21475930² = 922431138729800, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21475892 and 21475901.

It is not an unprimeable number, because it can be changed into a prime (21475939) 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, 7834 + ... + 10213.

It is an arithmetic number, because the mean of its divisors is an integer number (1461888).

Almost surely, 2^21475930 is an apocalyptic number.

21475930 is an abundant number, since it is smaller than the sum of its proper divisors (25304486).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21475930 is a wasteful number, since it uses less digits than its factorization.

21475930 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18078.

The product of its (nonzero) digits is 7560, while the sum is 31.

The square root of 21475930 is about 4634.2129860420. The cubic root of 21475930 is about 277.9610817973.

The spelling of 21475930 in words is "twenty-one million, four hundred seventy-five thousand, nine hundred thirty".