247391993 has 2 divisors, whose sum is σ = 247391994. Its totient is φ = 247391992.

The previous prime is 247391983. The next prime is 247392017. The reversal of 247391993 is 399193742.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 185722384 + 61669609 = 13628^2 + 7853^2 .

It is a cyclic number.

It is not a de Polignac number, because 247391993 - 2¹² = 247387897 is a prime.

It is a super-2 number, since 2×247391993² = 122405596401024098, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (247391983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 123695996 + 123695997.

It is an arithmetic number, because the mean of its divisors is an integer number (123695997).

Almost surely, 2^247391993 is an apocalyptic number.

It is an amenable number.

247391993 is a deficient number, since it is larger than the sum of its proper divisors (1).

247391993 is an equidigital number, since it uses as much as digits as its factorization.

247391993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 367416, while the sum is 47.

The square root of 247391993 is about 15728.6996601753. The cubic root of 247391993 is about 627.7622744517.

The spelling of 247391993 in words is "two hundred forty-seven million, three hundred ninety-one thousand, nine hundred ninety-three".