21770830 has 8 divisors (see below), whose sum is σ = 39187512. Its totient is φ = 8708328.

The previous prime is 21770803. The next prime is 21770831. The reversal of 21770830 is 3807712.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21770831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1088532 + ... + 1088551.

It is an arithmetic number, because the mean of its divisors is an integer number (4898439).

Almost surely, 2^21770830 is an apocalyptic number.

21770830 is a deficient number, since it is larger than the sum of its proper divisors (17416682).

21770830 is a wasteful number, since it uses less digits than its factorization.

21770830 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2177090.

The product of its (nonzero) digits is 2352, while the sum is 28.

The square root of 21770830 is about 4665.9222025233. The cubic root of 21770830 is about 279.2275905745.

The spelling of 21770830 in words is "twenty-one million, seven hundred seventy thousand, eight hundred thirty".