21221550340 has 48 divisors (see below), whose sum is σ = 46049794560. Its totient is φ = 8206410240.

The previous prime is 21221550269. The next prime is 21221550341. The reversal of 21221550340 is 4305512212.

It is not an unprimeable number, because it can be changed into a prime (21221550341) 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, 608619 + ... + 642541.

It is an arithmetic number, because the mean of its divisors is an integer number (959370720).

Almost surely, 2^21221550340 is an apocalyptic number.

21221550340 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 21221550340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23024897280).

21221550340 is an abundant number, since it is smaller than the sum of its proper divisors (24828244220).

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

21221550340 is a wasteful number, since it uses less digits than its factorization.

21221550340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34972 (or 34970 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 25.

The spelling of 21221550340 in words is "twenty-one billion, two hundred twenty-one million, five hundred fifty thousand, three hundred forty".