21420203452 has 48 divisors (see below), whose sum is σ = 38276761600. Its totient is φ = 10487102400.

The previous prime is 21420203407. The next prime is 21420203477. The reversal of 21420203452 is 25430202412.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14680699 + ... + 14682157.

Almost surely, 2^21420203452 is an apocalyptic number.

It is an amenable number.

21420203452 is a deficient number, since it is larger than the sum of its proper divisors (16856558148).

21420203452 is a wasteful number, since it uses less digits than its factorization.

21420203452 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1946 (or 1944 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 25.

Adding to 21420203452 its reverse (25430202412), we get a palindrome (46850405864).

The spelling of 21420203452 in words is "twenty-one billion, four hundred twenty million, two hundred three thousand, four hundred fifty-two".