31231728019 has 2 divisors, whose sum is σ = 31231728020. Its totient is φ = 31231728018.

The previous prime is 31231727999. The next prime is 31231728023. The reversal of 31231728019 is 91082713213.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 31231728019 - 2⁹ = 31231727507 is a prime.

It is a super-2 number, since 2×31231728019² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (31231728079) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15615864009 + 15615864010.

It is an arithmetic number, because the mean of its divisors is an integer number (15615864010).

Almost surely, 2^31231728019 is an apocalyptic number.

31231728019 is a deficient number, since it is larger than the sum of its proper divisors (1).

31231728019 is an equidigital number, since it uses as much as digits as its factorization.

31231728019 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18144, while the sum is 37.

The spelling of 31231728019 in words is "thirty-one billion, two hundred thirty-one million, seven hundred twenty-eight thousand, nineteen".