245771721 has 24 divisors (see below), whose sum is σ = 398938176. Its totient is φ = 144666720.

The previous prime is 245771719. The next prime is 245771749. The reversal of 245771721 is 127177542.

It is not a de Polignac number, because 245771721 - 2¹ = 245771719 is a prime.

It is not an unprimeable number, because it can be changed into a prime (245771711) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 42975 + ... + 48356.

It is an arithmetic number, because the mean of its divisors is an integer number (16622424).

Almost surely, 2^245771721 is an apocalyptic number.

It is an amenable number.

245771721 is a deficient number, since it is larger than the sum of its proper divisors (153166455).

245771721 is a wasteful number, since it uses less digits than its factorization.

245771721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91373 (or 91370 counting only the distinct ones).

The product of its digits is 27440, while the sum is 36.

The square root of 245771721 is about 15677.1081835905. The cubic root of 245771721 is about 626.3887803635.

The spelling of 245771721 in words is "two hundred forty-five million, seven hundred seventy-one thousand, seven hundred twenty-one".