21071010 has 64 divisors (see below), whose sum is σ = 52899840. Its totient is φ = 5365440.

The previous prime is 21071009. The next prime is 21071021. The reversal of 21071010 is 1017012.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 129189 + ... + 129351.

It is an arithmetic number, because the mean of its divisors is an integer number (826560).

Almost surely, 2^21071010 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21071010, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26449920).

21071010 is an abundant number, since it is smaller than the sum of its proper divisors (31828830).

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

21071010 is a wasteful number, since it uses less digits than its factorization.

21071010 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 343.

The product of its (nonzero) digits is 14, while the sum is 12.

The square root of 21071010 is about 4590.3169825187. The cubic root of 21071010 is about 276.2030379552.

Adding to 21071010 its reverse (1017012), we get a palindrome (22088022).

The spelling of 21071010 in words is "twenty-one million, seventy-one thousand, ten".