20727931 has 6 divisors (see below), whose sum is σ = 24112140. Its totient is φ = 17766756.

The previous prime is 20727911. The next prime is 20727979. The reversal of 20727931 is 13972702.

It is not a de Polignac number, because 20727931 - 2¹³ = 20719739 is a prime.

It is a super-2 number, since 2×20727931² = 859294247081522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20727893 and 20727902.

It is not an unprimeable number, because it can be changed into a prime (20727901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 211461 + ... + 211558.

It is an arithmetic number, because the mean of its divisors is an integer number (4018690).

Almost surely, 2^20727931 is an apocalyptic number.

20727931 is a deficient number, since it is larger than the sum of its proper divisors (3384209).

20727931 is an equidigital number, since it uses as much as digits as its factorization.

20727931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 423033 (or 423026 counting only the distinct ones).

The product of its (nonzero) digits is 5292, while the sum is 31.

The square root of 20727931 is about 4552.7937576833. The cubic root of 20727931 is about 274.6957781759.

The spelling of 20727931 in words is "twenty million, seven hundred twenty-seven thousand, nine hundred thirty-one".