21420604156 has 24 divisors (see below), whose sum is σ = 43128741600. Its totient is φ = 9118644672.

The previous prime is 21420604151. The next prime is 21420604181. The reversal of 21420604156 is 65140602412.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21420604151) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2563015 + ... + 2571358.

It is an arithmetic number, because the mean of its divisors is an integer number (1797030900).

Almost surely, 2^21420604156 is an apocalyptic number.

It is an amenable number.

21420604156 is an abundant number, since it is smaller than the sum of its proper divisors (21708137444).

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

21420604156 is a wasteful number, since it uses less digits than its factorization.

21420604156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5134533 (or 5134531 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 31.

The spelling of 21420604156 in words is "twenty-one billion, four hundred twenty million, six hundred four thousand, one hundred fifty-six".