4991257993 has 2 divisors, whose sum is σ = 4991257994. Its totient is φ = 4991257992.

The previous prime is 4991257963. The next prime is 4991258003. The reversal of 4991257993 is 3997521994.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3054993984 + 1936264009 = 55272^2 + 44003^2 .

It is a cyclic number.

It is not a de Polignac number, because 4991257993 - 2¹³ = 4991249801 is a prime.

It is not a weakly prime, because it can be changed into another prime (4991257933) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2495628996 + 2495628997.

It is an arithmetic number, because the mean of its divisors is an integer number (2495628997).

Almost surely, 2^4991257993 is an apocalyptic number.

It is an amenable number.

4991257993 is a deficient number, since it is larger than the sum of its proper divisors (1).

4991257993 is an equidigital number, since it uses as much as digits as its factorization.

4991257993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5511240, while the sum is 58.

The square root of 4991257993 is about 70648.8357511998. The cubic root of 4991257993 is about 1708.9787905279.

The spelling of 4991257993 in words is "four billion, nine hundred ninety-one million, two hundred fifty-seven thousand, nine hundred ninety-three".