21213504420 has 48 divisors (see below), whose sum is σ = 59552962560. Its totient is φ = 5642158336.

The previous prime is 21213504413. The next prime is 21213504439. The reversal of 21213504420 is 2440531212.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 438585 + ... + 484544.

It is an arithmetic number, because the mean of its divisors is an integer number (1240686720).

Almost surely, 2^21213504420 is an apocalyptic number.

21213504420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21213504420 is an abundant number, since it is smaller than the sum of its proper divisors (38339458140).

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

21213504420 is a wasteful number, since it uses less digits than its factorization.

21213504420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 923524 (or 923522 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 24.

The spelling of 21213504420 in words is "twenty-one billion, two hundred thirteen million, five hundred four thousand, four hundred twenty".