21316634850 has 144 divisors (see below), whose sum is σ = 63765793728. Its totient is φ = 4615850880.

The previous prime is 21316634827. The next prime is 21316634887. The reversal of 21316634850 is 5843661312.

It is a junction number, because it is equal to n+sod(n) for n = 21316634799 and 21316634808.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 350932 + ... + 407168.

It is an arithmetic number, because the mean of its divisors is an integer number (442818012).

Almost surely, 2^21316634850 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21316634850, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31882896864).

21316634850 is an abundant number, since it is smaller than the sum of its proper divisors (42449158878).

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

21316634850 is a wasteful number, since it uses less digits than its factorization.

21316634850 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56297 (or 56273 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 39.

The spelling of 21316634850 in words is "twenty-one billion, three hundred sixteen million, six hundred thirty-four thousand, eight hundred fifty".