21211223040 has 528 divisors, whose sum is σ = 88442190720. Its totient is φ = 4591779840.

The previous prime is 21211222961. The next prime is 21211223113. The reversal of 21211223040 is 4032211212.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6126910 + ... + 6130370.

Almost surely, 2^21211223040 is an apocalyptic number.

21211223040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21211223040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44221095360).

21211223040 is an abundant number, since it is smaller than the sum of its proper divisors (67230967680).

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

21211223040 is a wasteful number, since it uses less digits than its factorization.

21211223040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3518 (or 3497 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 21211223040 its reverse (4032211212), we get a palindrome (25243434252).

The spelling of 21211223040 in words is "twenty-one billion, two hundred eleven million, two hundred twenty-three thousand, forty".