21029610 has 64 divisors (see below), whose sum is σ = 58060800. Its totient is φ = 4775232.

The previous prime is 21029587. The next prime is 21029641. The reversal of 21029610 is 1692012.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Curzon number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 49981 + ... + 50399.

It is an arithmetic number, because the mean of its divisors is an integer number (907200).

Almost surely, 2^21029610 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21029610, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29030400).

21029610 is an abundant number, since it is smaller than the sum of its proper divisors (37031190).

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

21029610 is a wasteful number, since it uses less digits than its factorization.

21029610 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 675.

The product of its (nonzero) digits is 216, while the sum is 21.

The square root of 21029610 is about 4585.8052727956. The cubic root of 21029610 is about 276.0220261775.

The spelling of 21029610 in words is "twenty-one million, twenty-nine thousand, six hundred ten".