21000023340 has 48 divisors (see below), whose sum is σ = 58859566080. Its totient is φ = 5594339520.

The previous prime is 21000023333. The next prime is 21000023351. The reversal of 21000023340 is 4332000012.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 117130 + ... + 236049.

It is an arithmetic number, because the mean of its divisors is an integer number (1226240960).

Almost surely, 2^21000023340 is an apocalyptic number.

21000023340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21000023340 is an abundant number, since it is smaller than the sum of its proper divisors (37859542740).

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

21000023340 is a wasteful number, since it uses less digits than its factorization.

21000023340 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 354182 (or 354180 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 15.

Adding to 21000023340 its reverse (4332000012), we get a palindrome (25332023352).

The spelling of 21000023340 in words is "twenty-one billion, twenty-three thousand, three hundred forty".