2391487993 has 2 divisors, whose sum is σ = 2391487994. Its totient is φ = 2391487992.

The previous prime is 2391487961. The next prime is 2391488003. The reversal of 2391487993 is 3997841932.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2002294009 + 389193984 = 44747^2 + 19728^2 .

It is a cyclic number.

It is not a de Polignac number, because 2391487993 - 2⁵ = 2391487961 is a prime.

It is not a weakly prime, because it can be changed into another prime (2391487913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1195743996 + 1195743997.

It is an arithmetic number, because the mean of its divisors is an integer number (1195743997).

Almost surely, 2^2391487993 is an apocalyptic number.

It is an amenable number.

2391487993 is a deficient number, since it is larger than the sum of its proper divisors (1).

2391487993 is an equidigital number, since it uses as much as digits as its factorization.

2391487993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2939328, while the sum is 55.

The square root of 2391487993 is about 48902.8423816040. The cubic root of 2391487993 is about 1337.2811868789.

The spelling of 2391487993 in words is "two billion, three hundred ninety-one million, four hundred eighty-seven thousand, nine hundred ninety-three".