21004213340 has 36 divisors (see below), whose sum is σ = 48483284808. Its totient is φ = 7637894880.

The previous prime is 21004213297. The next prime is 21004213343. The reversal of 21004213340 is 4331240012.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21004213343) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4337294 + ... + 4342133.

Almost surely, 2^21004213340 is an apocalyptic number.

21004213340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21004213340 is an abundant number, since it is smaller than the sum of its proper divisors (27479071468).

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

21004213340 is a wasteful number, since it uses less digits than its factorization.

21004213340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8679458 (or 8679445 counting only the distinct ones).

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

Adding to 21004213340 its reverse (4331240012), we get a palindrome (25335453352).

The spelling of 21004213340 in words is "twenty-one billion, four million, two hundred thirteen thousand, three hundred forty".