21046830 has 128 divisors (see below), whose sum is σ = 61710336. Its totient is φ = 4492800.

The previous prime is 21046819. The next prime is 21046841. The reversal of 21046830 is 3864012.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21046819) and next prime (21046841).

It is a self number, because there is not a number n which added to its sum of digits gives 21046830.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 345000 + ... + 345060.

It is an arithmetic number, because the mean of its divisors is an integer number (482112).

Almost surely, 2^21046830 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21046830, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30855168).

21046830 is an abundant number, since it is smaller than the sum of its proper divisors (40663506).

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

21046830 is a wasteful number, since it uses less digits than its factorization.

21046830 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162.

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 21046830 is about 4587.6824214411. The cubic root of 21046830 is about 276.0973454143.

The spelling of 21046830 in words is "twenty-one million, forty-six thousand, eight hundred thirty".