245335721 has 4 divisors (see below), whose sum is σ = 259767252. Its totient is φ = 230904192.

The previous prime is 245335711. The next prime is 245335751. The reversal of 245335721 is 127533542.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 127533542 = 2 ⋅63766771.

It can be written as a sum of positive squares in 2 ways, for example, as 115261696 + 130074025 = 10736^2 + 11405^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-245335721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (245335711) 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, 7215740 + ... + 7215773.

It is an arithmetic number, because the mean of its divisors is an integer number (64941813).

Almost surely, 2^245335721 is an apocalyptic number.

It is an amenable number.

245335721 is a deficient number, since it is larger than the sum of its proper divisors (14431531).

245335721 is a wasteful number, since it uses less digits than its factorization.

245335721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14431530.

The product of its digits is 25200, while the sum is 32.

The square root of 245335721 is about 15663.1963851571. The cubic root of 245335721 is about 626.0181557269.

The spelling of 245335721 in words is "two hundred forty-five million, three hundred thirty-five thousand, seven hundred twenty-one".