21642010 has 32 divisors (see below), whose sum is σ = 42173712. Its totient is φ = 7948800.

The previous prime is 21641993. The next prime is 21642013. The reversal of 21642010 is 1024612.

It can be written as a sum of positive squares in 8 ways, for example, as 5489649 + 16152361 = 2343^2 + 4019^2 .

It is not an unprimeable number, because it can be changed into a prime (21642013) 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, 35710 + ... + 36310.

Almost surely, 2^21642010 is an apocalyptic number.

21642010 is a deficient number, since it is larger than the sum of its proper divisors (20531702).

21642010 is a wasteful number, since it uses less digits than its factorization.

21642010 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 898.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 21642010 is about 4652.0973764529. The cubic root of 21642010 is about 278.6757623027.

Adding to 21642010 its reverse (1024612), we get a palindrome (22666622).

The spelling of 21642010 in words is "twenty-one million, six hundred forty-two thousand, ten".