21213005040 has 60 divisors (see below), whose sum is σ = 71240344344. Its totient is φ = 5656801152.

The previous prime is 21213004961. The next prime is 21213005111. The reversal of 21213005040 is 4050031212.

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 14730534 + ... + 14731973.

Almost surely, 2^21213005040 is an apocalyptic number.

21213005040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21213005040 is an abundant number, since it is smaller than the sum of its proper divisors (50027339304).

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

21213005040 is a wasteful number, since it uses less digits than its factorization.

21213005040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29462526 (or 29462517 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

Adding to 21213005040 its reverse (4050031212), we get a palindrome (25263036252).

The spelling of 21213005040 in words is "twenty-one billion, two hundred thirteen million, five thousand, forty".