21142939788 has 60 divisors (see below), whose sum is σ = 55476006432. Its totient is φ = 7021611360.

The previous prime is 21142939777. The next prime is 21142939789. The reversal of 21142939788 is 88793924112.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (21142939789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 32595 + ... + 208202.

Almost surely, 2^21142939788 is an apocalyptic number.

It is an amenable number.

21142939788 is an abundant number, since it is smaller than the sum of its proper divisors (34333066644).

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

21142939788 is a wasteful number, since it uses less digits than its factorization.

21142939788 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 241084 (or 241073 counting only the distinct ones).

The product of its digits is 1741824, while the sum is 54.

The spelling of 21142939788 in words is "twenty-one billion, one hundred forty-two million, nine hundred thirty-nine thousand, seven hundred eighty-eight".