21420202 has 8 divisors (see below), whose sum is σ = 32271300. Its totient is φ = 10663104.

The previous prime is 21420169. The next prime is 21420209. The reversal of 21420202 is 20202412.

It can be written as a sum of positive squares in 2 ways, for example, as 21169201 + 251001 = 4601^2 + 501^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (21420209) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22927 + ... + 23842.

Almost surely, 2^21420202 is an apocalyptic number.

21420202 is a deficient number, since it is larger than the sum of its proper divisors (10851098).

21420202 is a wasteful number, since it uses less digits than its factorization.

21420202 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47000.

The product of its (nonzero) digits is 64, while the sum is 13.

The square root of 21420202 is about 4628.1964089697. The cubic root of 21420202 is about 277.7204459930.

Adding to 21420202 its reverse (20202412), we get a palindrome (41622614).

The spelling of 21420202 in words is "twenty-one million, four hundred twenty thousand, two hundred two".