247997993 has 4 divisors (see below), whose sum is σ = 248043780. Its totient is φ = 247952208.

The previous prime is 247997969. The next prime is 247998007. The reversal of 247997993 is 399799742.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 164147344 + 83850649 = 12812^2 + 9157^2 .

It is a cyclic number.

It is not a de Polignac number, because 247997993 - 2²² = 243803689 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (247997093) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13478 + ... + 26031.

It is an arithmetic number, because the mean of its divisors is an integer number (62010945).

Almost surely, 2^247997993 is an apocalyptic number.

It is an amenable number.

247997993 is a deficient number, since it is larger than the sum of its proper divisors (45787).

247997993 is an equidigital number, since it uses as much as digits as its factorization.

247997993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45786.

The product of its digits is 7715736, while the sum is 59.

The square root of 247997993 is about 15747.9520255810. The cubic root of 247997993 is about 628.2744356482.

The spelling of 247997993 in words is "two hundred forty-seven million, nine hundred ninety-seven thousand, nine hundred ninety-three".