21010010 has 32 divisors (see below), whose sum is σ = 45498240. Its totient is φ = 6823872.

The previous prime is 21009997. The next prime is 21010013. The reversal of 21010010 is 1001012.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (5).

It is a junction number, because it is equal to n+sod(n) for n = 21009976 and 21010003.

It is not an unprimeable number, because it can be changed into a prime (21010013) 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, 6569 + ... + 9228.

It is an arithmetic number, because the mean of its divisors is an integer number (1421820).

Almost surely, 2^21010010 is an apocalyptic number.

21010010 is an abundant number, since it is smaller than the sum of its proper divisors (24488230).

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

21010010 is a wasteful number, since it uses less digits than its factorization.

21010010 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15830.

The product of its (nonzero) digits is 2, while the sum is 5.

The square root of 21010010 is about 4583.6677453760. The cubic root of 21010010 is about 275.9362469146.

Adding to 21010010 its reverse (1001012), we get a palindrome (22011022).

The spelling of 21010010 in words is "twenty-one million, ten thousand, ten".