21310830 has 32 divisors (see below), whose sum is σ = 56829600. Its totient is φ = 5682816.

The previous prime is 21310819. The next prime is 21310841. The reversal of 21310830 is 3801312.

It is an interprime number because it is at equal distance from previous prime (21310819) and next prime (21310841).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a Curzon number.

It is a zygodrome in base 3.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39195 + ... + 39734.

It is an arithmetic number, because the mean of its divisors is an integer number (1775925).

Almost surely, 2^21310830 is an apocalyptic number.

21310830 is an abundant number, since it is smaller than the sum of its proper divisors (35518770).

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

21310830 is a wasteful number, since it uses less digits than its factorization.

21310830 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78945 (or 78939 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 21310830 is about 4616.3654534709. The cubic root of 21310830 is about 277.2469570570.

The spelling of 21310830 in words is "twenty-one million, three hundred ten thousand, eight hundred thirty".