21213320240 has 80 divisors (see below), whose sum is σ = 57208219392. Its totient is φ = 7164571392.

The previous prime is 21213320237. The next prime is 21213320291. The reversal of 21213320240 is 4202331212.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 245174 + ... + 320213.

Almost surely, 2^21213320240 is an apocalyptic number.

21213320240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21213320240 is an abundant number, since it is smaller than the sum of its proper divisors (35994899152).

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

21213320240 is a wasteful number, since it uses less digits than its factorization.

21213320240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 565474 (or 565468 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 21213320240 its reverse (4202331212), we get a palindrome (25415651452).

The spelling of 21213320240 in words is "twenty-one billion, two hundred thirteen million, three hundred twenty thousand, two hundred forty".