21105949948 has 12 divisors (see below), whose sum is σ = 36991979640. Its totient is φ = 10536812912.

The previous prime is 21105949937. The next prime is 21105949951. The reversal of 21105949948 is 84994950112.

It is a super-2 number, since 2×21105949948² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21105949895 and 21105949904.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4037578 + ... + 4042801.

It is an arithmetic number, because the mean of its divisors is an integer number (3082664970).

Almost surely, 2^21105949948 is an apocalyptic number.

It is an amenable number.

21105949948 is a deficient number, since it is larger than the sum of its proper divisors (15886029692).

21105949948 is a wasteful number, since it uses less digits than its factorization.

21105949948 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8081036 (or 8081034 counting only the distinct ones).

The product of its (nonzero) digits is 933120, while the sum is 52.

The spelling of 21105949948 in words is "twenty-one billion, one hundred five million, nine hundred forty-nine thousand, nine hundred forty-eight".