20930391 has 12 divisors (see below), whose sum is σ = 31547568. Its totient is φ = 13346784.

The previous prime is 20930387. The next prime is 20930401. The reversal of 20930391 is 19303902.

It is not a de Polignac number, because 20930391 - 2² = 20930387 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20930891) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 50350 + ... + 50763.

It is an arithmetic number, because the mean of its divisors is an integer number (2628964).

Almost surely, 2^20930391 is an apocalyptic number.

20930391 is a deficient number, since it is larger than the sum of its proper divisors (10617177).

20930391 is a wasteful number, since it uses less digits than its factorization.

20930391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101142 (or 101139 counting only the distinct ones).

The product of its (nonzero) digits is 1458, while the sum is 27.

The square root of 20930391 is about 4574.9744261580. The cubic root of 20930391 is about 275.5872453570.

It can be divided in two parts, 20930 and 391, that added together give a triangular number (21321 = T₂₀₆).

The spelling of 20930391 in words is "twenty million, nine hundred thirty thousand, three hundred ninety-one".