21151330 has 8 divisors (see below), whose sum is σ = 38072412. Its totient is φ = 8460528.

The previous prime is 21151307. The next prime is 21151343. The reversal of 21151330 is 3315112.

It can be written as a sum of positive squares in 2 ways, for example, as 21150801 + 529 = 4599^2 + 23^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1057557 + ... + 1057576.

Almost surely, 2^21151330 is an apocalyptic number.

21151330 is a deficient number, since it is larger than the sum of its proper divisors (16921082).

21151330 is a wasteful number, since it uses less digits than its factorization.

21151330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2115140.

The product of its (nonzero) digits is 90, while the sum is 16.

The square root of 21151330 is about 4599.0575121431. The cubic root of 21151330 is about 276.5535432106.

Adding to 21151330 its reverse (3315112), we get a palindrome (24466442).

The spelling of 21151330 in words is "twenty-one million, one hundred fifty-one thousand, three hundred thirty".