21180698742 has 96 divisors (see below), whose sum is σ = 52007201280. Its totient is φ = 5718081600.

The previous prime is 21180698741. The next prime is 21180698839. The reversal of 21180698742 is 24789608112.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21180698691 and 21180698700.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21180698741) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2212867 + ... + 2222417.

It is an arithmetic number, because the mean of its divisors is an integer number (541741680).

Almost surely, 2^21180698742 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21180698742, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26003600640).

21180698742 is an abundant number, since it is smaller than the sum of its proper divisors (30826502538).

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

21180698742 is a wasteful number, since it uses less digits than its factorization.

21180698742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9986 (or 9979 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 48.

The spelling of 21180698742 in words is "twenty-one billion, one hundred eighty million, six hundred ninety-eight thousand, seven hundred forty-two".