21204030040 has 32 divisors (see below), whose sum is σ = 48025035360. Its totient is φ = 8425440000.

The previous prime is 21204030037. The next prime is 21204030047. The reversal of 21204030040 is 4003040212.

It is a super-2 number, since 2×21204030040² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21204029996 and 21204030023.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21204030047) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1749261 + ... + 1761340.

It is an arithmetic number, because the mean of its divisors is an integer number (1500782355).

Almost surely, 2^21204030040 is an apocalyptic number.

21204030040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21204030040 is an abundant number, since it is smaller than the sum of its proper divisors (26821005320).

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

21204030040 is a wasteful number, since it uses less digits than its factorization.

21204030040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3510763 (or 3510759 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 16.

Adding to 21204030040 its reverse (4003040212), we get a palindrome (25207070252).

The spelling of 21204030040 in words is "twenty-one billion, two hundred four million, thirty thousand, forty".