19910939 has 16 divisors (see below), whose sum is σ = 21537792. Its totient is φ = 18361728.

The previous prime is 19910903. The next prime is 19910951. The reversal of 19910939 is 93901991.

It is a de Polignac number, because none of the positive numbers 2^k-19910939 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 19910896 and 19910905.

It is not an unprimeable number, because it can be changed into a prime (19910999) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 122072 + ... + 122234.

It is an arithmetic number, because the mean of its divisors is an integer number (1346112).

Almost surely, 2^19910939 is an apocalyptic number.

19910939 is a deficient number, since it is larger than the sum of its proper divisors (1626853).

19910939 is a wasteful number, since it uses less digits than its factorization.

19910939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 346.

The product of its (nonzero) digits is 19683, while the sum is 41.

The square root of 19910939 is about 4462.1675226284. The cubic root of 19910939 is about 271.0382475303.

The spelling of 19910939 in words is "nineteen million, nine hundred ten thousand, nine hundred thirty-nine".