20051931 has 4 divisors (see below), whose sum is σ = 26735912. Its totient is φ = 13367952.

The previous prime is 20051921. The next prime is 20051951. The reversal of 20051931 is 13915002.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20051931 - 2¹³ = 20043739 is a prime.

It is a super-2 number, since 2×20051931² = 804159873657522, 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 = 20051898 and 20051907.

It is not an unprimeable number, because it can be changed into a prime (20051921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3341986 + ... + 3341991.

It is an arithmetic number, because the mean of its divisors is an integer number (6683978).

Almost surely, 2^20051931 is an apocalyptic number.

20051931 is a deficient number, since it is larger than the sum of its proper divisors (6683981).

20051931 is an equidigital number, since it uses as much as digits as its factorization.

20051931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6683980.

The product of its (nonzero) digits is 270, while the sum is 21.

The square root of 20051931 is about 4477.9382532590. The cubic root of 20051931 is about 271.6764959788.

Adding to 20051931 its reverse (13915002), we get a palindrome (33966933).

The spelling of 20051931 in words is "twenty million, fifty-one thousand, nine hundred thirty-one".