20540731 has 2 divisors, whose sum is σ = 20540732. Its totient is φ = 20540730.

The previous prime is 20540719. The next prime is 20540747. The reversal of 20540731 is 13704502.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20540731 - 2⁵ = 20540699 is a prime.

It is a super-2 number, since 2×20540731² = 843843260028722, which contains 22 as substring.

It is equal to p_1302673 and since 20540731 and 1302673 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (20540761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10270365 + 10270366.

It is an arithmetic number, because the mean of its divisors is an integer number (10270366).

Almost surely, 2^20540731 is an apocalyptic number.

20540731 is a deficient number, since it is larger than the sum of its proper divisors (1).

20540731 is an equidigital number, since it uses as much as digits as its factorization.

20540731 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 840, while the sum is 22.

The square root of 20540731 is about 4532.1883235364. The cubic root of 20540731 is about 273.8663235199.

The spelling of 20540731 in words is "twenty million, five hundred forty thousand, seven hundred thirty-one".