501039991 has 2 divisors, whose sum is σ = 501039992. Its totient is φ = 501039990.

The previous prime is 501039961. The next prime is 501040021. The reversal of 501039991 is 199930105.

It is a balanced prime because it is at equal distance from previous prime (501039961) and next prime (501040021).

It is a cyclic number.

It is not a de Polignac number, because 501039991 - 2⁹ = 501039479 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 501039991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (501039961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 250519995 + 250519996.

It is an arithmetic number, because the mean of its divisors is an integer number (250519996).

Almost surely, 2^501039991 is an apocalyptic number.

501039991 is a deficient number, since it is larger than the sum of its proper divisors (1).

501039991 is an equidigital number, since it uses as much as digits as its factorization.

501039991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10935, while the sum is 37.

The square root of 501039991 is about 22383.9226008312. The cubic root of 501039991 is about 794.2504391595.

The spelling of 501039991 in words is "five hundred one million, thirty-nine thousand, nine hundred ninety-one".