211220024420 has 12 divisors (see below), whose sum is σ = 443562051324. Its totient is φ = 84488009760.

The previous prime is 211220024399. The next prime is 211220024461. The reversal of 211220024420 is 24420022112.

It can be written as a sum of positive squares in 2 ways, for example, as 130750220836 + 80469803584 = 361594^2 + 283672^2 .

It is a super-2 number, since 2×211220024420² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20), and also a Moran number because the ratio is a prime number: 10561001221 = 211220024420 / (2 + 1 + 1 + 2 + 2 + 0 + 0 + 2 + 4 + 4 + 2 + 0).

It is a junction number, because it is equal to n+sod(n) for n = 211220024392 and 211220024401.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5280500591 + ... + 5280500630.

It is an arithmetic number, because the mean of its divisors is an integer number (36963504277).

Almost surely, 2^211220024420 is an apocalyptic number.

211220024420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

211220024420 is an abundant number, since it is smaller than the sum of its proper divisors (232342026904).

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

211220024420 is a wasteful number, since it uses less digits than its factorization.

211220024420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10561001230 (or 10561001228 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 20.

Adding to 211220024420 its reverse (24420022112), we get a palindrome (235640046532).

The spelling of 211220024420 in words is "two hundred eleven billion, two hundred twenty million, twenty-four thousand, four hundred twenty".