21115474 has 4 divisors (see below), whose sum is σ = 31673214. Its totient is φ = 10557736.

The previous prime is 21115453. The next prime is 21115511. The reversal of 21115474 is 47451112.

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., 18533025 + 2582449 = 4305^2 + 1607^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5278867 + ... + 5278870.

Almost surely, 2^21115474 is an apocalyptic number.

21115474 is a deficient number, since it is larger than the sum of its proper divisors (10557740).

21115474 is a wasteful number, since it uses less digits than its factorization.

21115474 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10557739.

The product of its digits is 1120, while the sum is 25.

The square root of 21115474 is about 4595.1576686769. The cubic root of 21115474 is about 276.3971824770.

Adding to 21115474 its reverse (47451112), we get a palindrome (68566586).

The spelling of 21115474 in words is "twenty-one million, one hundred fifteen thousand, four hundred seventy-four".