21091738250 has 32 divisors (see below), whose sum is σ = 43073169984. Its totient is φ = 7669722000.

The previous prime is 21091738219. The next prime is 21091738303. The reversal of 21091738250 is 5283719012.

It is a super-2 number, since 2×21091738250² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3832112 + ... + 3837611.

It is an arithmetic number, because the mean of its divisors is an integer number (1346036562).

Almost surely, 2^21091738250 is an apocalyptic number.

21091738250 is an abundant number, since it is smaller than the sum of its proper divisors (21981431734).

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

21091738250 is a wasteful number, since it uses less digits than its factorization.

21091738250 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7669751 (or 7669741 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 38.

The spelling of 21091738250 in words is "twenty-one billion, ninety-one million, seven hundred thirty-eight thousand, two hundred fifty".