21003910939 has 8 divisors (see below), whose sum is σ = 23703473520. Its totient is φ = 18436034400.

The previous prime is 21003910927. The next prime is 21003910957. The reversal of 21003910939 is 93901930012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21003910939 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21003910898 and 21003910907.

It is not an unprimeable number, because it can be changed into a prime (21003910439) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 32921172 + ... + 32921809.

It is an arithmetic number, because the mean of its divisors is an integer number (2962934190).

Almost surely, 2^21003910939 is an apocalyptic number.

21003910939 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

21003910939 is a deficient number, since it is larger than the sum of its proper divisors (2699562581).

21003910939 is a wasteful number, since it uses less digits than its factorization.

21003910939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65843021.

The product of its (nonzero) digits is 13122, while the sum is 37.

The spelling of 21003910939 in words is "twenty-one billion, three million, nine hundred ten thousand, nine hundred thirty-nine".