21331476 has 36 divisors (see below), whose sum is σ = 54666612. Its totient is φ = 7012224.

The previous prime is 21331469. The next prime is 21331477. The reversal of 21331476 is 67413312.

It can be written as a sum of positive squares in 2 ways, for example, as 16160400 + 5171076 = 4020^2 + 2274^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21331477) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1431 + ... + 6686.

It is an arithmetic number, because the mean of its divisors is an integer number (1518517).

Almost surely, 2^21331476 is an apocalyptic number.

It is an amenable number.

21331476 is an abundant number, since it is smaller than the sum of its proper divisors (33335136).

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

21331476 is a wasteful number, since it uses less digits than its factorization.

21331476 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8200 (or 8195 counting only the distinct ones).

The product of its digits is 3024, while the sum is 27.

The square root of 21331476 is about 4618.6010869093. The cubic root of 21331476 is about 277.3364607379.

Adding to 21331476 its reverse (67413312), we get a palindrome (88744788).

The spelling of 21331476 in words is "twenty-one million, three hundred thirty-one thousand, four hundred seventy-six".