21034213220 has 24 divisors (see below), whose sum is σ = 46770192504. Its totient is φ = 7918762496.

The previous prime is 21034213201. The next prime is 21034213301. The reversal of 21034213220 is 2231243012.

It can be written as a sum of positive squares in 4 ways, for example, as 11507281984 + 9526931236 = 107272^2 + 97606^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 21034213192 and 21034213201.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30932327 + ... + 30933006.

It is an arithmetic number, because the mean of its divisors is an integer number (1948758021).

Almost surely, 2^21034213220 is an apocalyptic number.

21034213220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21034213220 is an abundant number, since it is smaller than the sum of its proper divisors (25735979284).

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

21034213220 is a wasteful number, since it uses less digits than its factorization.

21034213220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61865359 (or 61865357 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 21034213220 its reverse (2231243012), we get a palindrome (23265456232).

The spelling of 21034213220 in words is "twenty-one billion, thirty-four million, two hundred thirteen thousand, two hundred twenty".