21415936 has 24 divisors (see below), whose sum is σ = 42825510. Its totient is φ = 10706944.

The previous prime is 21415931. The next prime is 21415969. The reversal of 21415936 is 63951412.

It can be written as a sum of positive squares in only one way, i.e., 14017536 + 7398400 = 3744^2 + 2720^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21415898 and 21415907.

It is not an unprimeable number, because it can be changed into a prime (21415931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3181 + ... + 7276.

Almost surely, 2^21415936 is an apocalyptic number.

It is an amenable number.

21415936 is a deficient number, since it is larger than the sum of its proper divisors (21409574).

21415936 is an equidigital number, since it uses as much as digits as its factorization.

21415936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10479 (or 10459 counting only the distinct ones).

The product of its digits is 6480, while the sum is 31.

The square root of 21415936 is about 4627.7355153466. The cubic root of 21415936 is about 277.7020080393.

The spelling of 21415936 in words is "twenty-one million, four hundred fifteen thousand, nine hundred thirty-six".