21014001220 has 12 divisors (see below), whose sum is σ = 44129402604. Its totient is φ = 8405600480.

The previous prime is 21014001191. The next prime is 21014001233. The reversal of 21014001220 is 2210041012.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 6096798724 + 14917202496 = 78082^2 + 122136^2 .

It is a super-2 number, since 2×21014001220² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21014001220.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 525350011 + ... + 525350050.

It is an arithmetic number, because the mean of its divisors is an integer number (3677450217).

Almost surely, 2^21014001220 is an apocalyptic number.

21014001220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21014001220 is an abundant number, since it is smaller than the sum of its proper divisors (23115401384).

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

21014001220 is a wasteful number, since it uses less digits than its factorization.

21014001220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1050700070 (or 1050700068 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21014001220 its reverse (2210041012), we get a palindrome (23224042232).

The spelling of 21014001220 in words is "twenty-one billion, fourteen million, one thousand, two hundred twenty".