21205330620 has 48 divisors (see below), whose sum is σ = 59929849728. Its totient is φ = 5601904960.

The previous prime is 21205330583. The next prime is 21205330637. The reversal of 21205330620 is 2603350212.

It is a congruent number.

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, 1645086 + ... + 1657925.

It is an arithmetic number, because the mean of its divisors is an integer number (1248538536).

Almost surely, 2^21205330620 is an apocalyptic number.

21205330620 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21205330620 is an abundant number, since it is smaller than the sum of its proper divisors (38724519108).

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

21205330620 is a wasteful number, since it uses less digits than its factorization.

21205330620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3303130 (or 3303128 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 24.

Adding to 21205330620 its reverse (2603350212), we get a palindrome (23808680832).

The spelling of 21205330620 in words is "twenty-one billion, two hundred five million, three hundred thirty thousand, six hundred twenty".