245721571 has 2 divisors, whose sum is σ = 245721572. Its totient is φ = 245721570.

The previous prime is 245721563. The next prime is 245721601. The reversal of 245721571 is 175127542.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 245721571 - 2³ = 245721563 is a prime.

It is not a weakly prime, because it can be changed into another prime (245721071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 122860785 + 122860786.

It is an arithmetic number, because the mean of its divisors is an integer number (122860786).

Almost surely, 2^245721571 is an apocalyptic number.

245721571 is a deficient number, since it is larger than the sum of its proper divisors (1).

245721571 is an equidigital number, since it uses as much as digits as its factorization.

245721571 is an evil number, because the sum of its binary digits is even.

The product of its digits is 19600, while the sum is 34.

The square root of 245721571 is about 15675.5086360858. The cubic root of 245721571 is about 626.3461723503.

The spelling of 245721571 in words is "two hundred forty-five million, seven hundred twenty-one thousand, five hundred seventy-one".