21210011040 has 96 divisors (see below), whose sum is σ = 66850793856. Its totient is φ = 5652679680.

The previous prime is 21210011033. The next prime is 21210011041. The reversal of 21210011040 is 4011001212.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (12).

It is not an unprimeable number, because it can be changed into a prime (21210011041) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 866814 + ... + 890946.

It is an arithmetic number, because the mean of its divisors is an integer number (696362436).

Almost surely, 2^21210011040 is an apocalyptic number.

21210011040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21210011040 is an abundant number, since it is smaller than the sum of its proper divisors (45640782816).

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

21210011040 is a wasteful number, since it uses less digits than its factorization.

21210011040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25982 (or 25974 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21210011040 its reverse (4011001212), we get a palindrome (25221012252).

The spelling of 21210011040 in words is "twenty-one billion, two hundred ten million, eleven thousand, forty".