719931991 has 2 divisors, whose sum is σ = 719931992. Its totient is φ = 719931990.

The previous prime is 719931973. The next prime is 719932007. The reversal of 719931991 is 199139917.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 719931991 - 2⁵ = 719931959 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (719931491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 359965995 + 359965996.

It is an arithmetic number, because the mean of its divisors is an integer number (359965996).

Almost surely, 2^719931991 is an apocalyptic number.

719931991 is a deficient number, since it is larger than the sum of its proper divisors (1).

719931991 is an equidigital number, since it uses as much as digits as its factorization.

719931991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 137781, while the sum is 49.

The square root of 719931991 is about 26831.5484271780. The cubic root of 719931991 is about 896.2527284362.

It can be divided in two parts, 71993 and 1991, that added together give a square (73984 = 272²).

The spelling of 719931991 in words is "seven hundred nineteen million, nine hundred thirty-one thousand, nine hundred ninety-one".