245991791 has 4 divisors (see below), whose sum is σ = 246053784. Its totient is φ = 245929800.

The previous prime is 245991769. The next prime is 245991793. The reversal of 245991791 is 197199542.

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

It is a cyclic number.

It is not a de Polignac number, because 245991791 - 2¹⁸ = 245729647 is a prime.

It is a super-2 number, since 2×245991791² = 121023922478775362, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (245991793) 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, 24605 + ... + 33126.

It is an arithmetic number, because the mean of its divisors is an integer number (61513446).

Almost surely, 2^245991791 is an apocalyptic number.

245991791 is a deficient number, since it is larger than the sum of its proper divisors (61993).

245991791 is an equidigital number, since it uses as much as digits as its factorization.

245991791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61992.

The product of its digits is 204120, while the sum is 47.

The square root of 245991791 is about 15684.1254458130. The cubic root of 245991791 is about 626.5756858575.

The spelling of 245991791 in words is "two hundred forty-five million, nine hundred ninety-one thousand, seven hundred ninety-one".