21263474 has 4 divisors (see below), whose sum is σ = 31895214. Its totient is φ = 10631736.

The previous prime is 21263471. The next prime is 21263497. The reversal of 21263474 is 47436212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 19140625 + 2122849 = 4375^2 + 1457^2 .

It is not an unprimeable number, because it can be changed into a prime (21263471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5315867 + ... + 5315870.

Almost surely, 2^21263474 is an apocalyptic number.

21263474 is a deficient number, since it is larger than the sum of its proper divisors (10631740).

21263474 is a wasteful number, since it uses less digits than its factorization.

21263474 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10631739.

The product of its digits is 8064, while the sum is 29.

The square root of 21263474 is about 4611.2334575469. The cubic root of 21263474 is about 277.0414427083.

Adding to 21263474 its reverse (47436212), we get a palindrome (68699686).

The spelling of 21263474 in words is "twenty-one million, two hundred sixty-three thousand, four hundred seventy-four".