21131330 has 16 divisors (see below), whose sum is σ = 41494464. Its totient is φ = 7684080.

The previous prime is 21131317. The next prime is 21131333. The reversal of 21131330 is 3313112.

It is not an unprimeable number, because it can be changed into a prime (21131333) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 95942 + ... + 96161.

It is an arithmetic number, because the mean of its divisors is an integer number (2593404).

Almost surely, 2^21131330 is an apocalyptic number.

21131330 is a deficient number, since it is larger than the sum of its proper divisors (20363134).

21131330 is a wasteful number, since it uses less digits than its factorization.

21131330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 192121.

The product of its (nonzero) digits is 54, while the sum is 14.

The square root of 21131330 is about 4596.8826393546. The cubic root of 21131330 is about 276.4663490860.

Adding to 21131330 its reverse (3313112), we get a palindrome (24444442).

It can be divided in two parts, 2113 and 1330, that added together give a palindrome (3443).

The spelling of 21131330 in words is "twenty-one million, one hundred thirty-one thousand, three hundred thirty".