21139139840 has 288 divisors, whose sum is σ = 62854471680. Its totient is φ = 6632865792.

The previous prime is 21139139839. The next prime is 21139139843. The reversal of 21139139840 is 4893193112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21139139843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 14792246 + ... + 14793674.

Almost surely, 2^21139139840 is an apocalyptic number.

21139139840 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21139139840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31427235840).

21139139840 is an abundant number, since it is smaller than the sum of its proper divisors (41715331840).

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

21139139840 is a wasteful number, since it uses less digits than its factorization.

21139139840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1597 (or 1583 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 41.

The spelling of 21139139840 in words is "twenty-one billion, one hundred thirty-nine million, one hundred thirty-nine thousand, eight hundred forty".