245130721 has 4 divisors (see below), whose sum is σ = 267415344. Its totient is φ = 222846100.

The previous prime is 245130719. The next prime is 245130773. The reversal of 245130721 is 127031542.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 245130721 - 2¹ = 245130719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (245130791) 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, 11142295 + ... + 11142316.

It is an arithmetic number, because the mean of its divisors is an integer number (66853836).

Almost surely, 2^245130721 is an apocalyptic number.

It is an amenable number.

245130721 is a deficient number, since it is larger than the sum of its proper divisors (22284623).

245130721 is a wasteful number, since it uses less digits than its factorization.

245130721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22284622.

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 245130721 is about 15656.6510148243. The cubic root of 245130721 is about 625.8437423655.

The spelling of 245130721 in words is "two hundred forty-five million, one hundred thirty thousand, seven hundred twenty-one".