21007210 has 32 divisors (see below), whose sum is σ = 43817472. Its totient is φ = 7102080.

The previous prime is 21007201. The next prime is 21007213. The reversal of 21007210 is 1270012.

21007210 = T₁₄₀ + T₁₄₁ + ... + T₅₀₄.

It is not an unprimeable number, because it can be changed into a prime (21007213) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3055 + ... + 7165.

It is an arithmetic number, because the mean of its divisors is an integer number (1369296).

Almost surely, 2^21007210 is an apocalyptic number.

21007210 is an abundant number, since it is smaller than the sum of its proper divisors (22810262).

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

21007210 is a wasteful number, since it uses less digits than its factorization.

21007210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4198.

The product of its (nonzero) digits is 28, while the sum is 13.

The square root of 21007210 is about 4583.3623029387. The cubic root of 21007210 is about 275.9239883798.

Adding to 21007210 its reverse (1270012), we get a palindrome (22277222).

The spelling of 21007210 in words is "twenty-one million, seven thousand, two hundred ten".