21204142140 has 96 divisors (see below), whose sum is σ = 59721984000. Its totient is φ = 5621156352.

The previous prime is 21204142117. The next prime is 21204142153. The reversal of 21204142140 is 4124140212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13177656 + ... + 13179264.

It is an arithmetic number, because the mean of its divisors is an integer number (622104000).

Almost surely, 2^21204142140 is an apocalyptic number.

21204142140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21204142140 is an abundant number, since it is smaller than the sum of its proper divisors (38517841860).

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

21204142140 is a wasteful number, since it uses less digits than its factorization.

21204142140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2779 (or 2777 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 21.

Adding to 21204142140 its reverse (4124140212), we get a palindrome (25328282352).

The spelling of 21204142140 in words is "twenty-one billion, two hundred four million, one hundred forty-two thousand, one hundred forty".