21420653213 has 4 divisors (see below), whose sum is σ = 21876411840. Its totient is φ = 20964894588.

The previous prime is 21420653209. The next prime is 21420653231. The reversal of 21420653213 is 31235602412.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21420653213 - 2² = 21420653209 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21420650213) 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, 227879243 + ... + 227879336.

It is an arithmetic number, because the mean of its divisors is an integer number (5469102960).

Almost surely, 2^21420653213 is an apocalyptic number.

It is an amenable number.

21420653213 is a deficient number, since it is larger than the sum of its proper divisors (455758627).

21420653213 is an equidigital number, since it uses as much as digits as its factorization.

21420653213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 455758626.

The product of its (nonzero) digits is 8640, while the sum is 29.

The spelling of 21420653213 in words is "twenty-one billion, four hundred twenty million, six hundred fifty-three thousand, two hundred thirteen".