21323020340 has 24 divisors (see below), whose sum is σ = 44869561632. Its totient is φ = 8511833120.

The previous prime is 21323020309. The next prime is 21323020357. The reversal of 21323020340 is 4302032312.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1075874 + ... + 1095513.

It is an arithmetic number, because the mean of its divisors is an integer number (1869565068).

Almost surely, 2^21323020340 is an apocalyptic number.

21323020340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21323020340 is an abundant number, since it is smaller than the sum of its proper divisors (23546541292).

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

21323020340 is a wasteful number, since it uses less digits than its factorization.

21323020340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2171887 (or 2171885 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 20.

Adding to 21323020340 its reverse (4302032312), we get a palindrome (25625052652).

The spelling of 21323020340 in words is "twenty-one billion, three hundred twenty-three million, twenty thousand, three hundred forty".