1023231991 has 2 divisors, whose sum is σ = 1023231992. Its totient is φ = 1023231990.

The previous prime is 1023231983. The next prime is 1023231997. The reversal of 1023231991 is 1991323201.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1023231991 - 2³ = 1023231983 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1023231997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 511615995 + 511615996.

It is an arithmetic number, because the mean of its divisors is an integer number (511615996).

Almost surely, 2^1023231991 is an apocalyptic number.

1023231991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1023231991 is an equidigital number, since it uses as much as digits as its factorization.

1023231991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2916, while the sum is 31.

The square root of 1023231991 is about 31987.9976084781. The cubic root of 1023231991 is about 1007.6847897292.

The spelling of 1023231991 in words is "one billion, twenty-three million, two hundred thirty-one thousand, nine hundred ninety-one".