21131476 has 24 divisors (see below), whose sum is σ = 39384576. Its totient is φ = 9886080.

The previous prime is 21131449. The next prime is 21131489. The reversal of 21131476 is 67413112.

It is a self number, because there is not a number n which added to its sum of digits gives 21131476.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12175 + ... + 13801.

It is an arithmetic number, because the mean of its divisors is an integer number (1641024).

Almost surely, 2^21131476 is an apocalyptic number.

It is an amenable number.

21131476 is a deficient number, since it is larger than the sum of its proper divisors (18253100).

21131476 is a wasteful number, since it uses less digits than its factorization.

21131476 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1839 (or 1837 counting only the distinct ones).

The product of its digits is 1008, while the sum is 25.

The square root of 21131476 is about 4596.8985196543. The cubic root of 21131476 is about 276.4669858024.

Adding to 21131476 its reverse (67413112), we get a palindrome (88544588).

The spelling of 21131476 in words is "twenty-one million, one hundred thirty-one thousand, four hundred seventy-six".