245533721 has 4 divisors (see below), whose sum is σ = 245889744. Its totient is φ = 245177700.

The previous prime is 245533699. The next prime is 245533753. The reversal of 245533721 is 127335542.

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 245533721 - 2⁶ = 245533657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (245533621) 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, 176975 + ... + 178356.

It is an arithmetic number, because the mean of its divisors is an integer number (61472436).

Almost surely, 2^245533721 is an apocalyptic number.

It is an amenable number.

245533721 is a deficient number, since it is larger than the sum of its proper divisors (356023).

245533721 is an equidigital number, since it uses as much as digits as its factorization.

245533721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 356022.

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

The square root of 245533721 is about 15669.5156593942. The cubic root of 245533721 is about 626.1865212954.

The spelling of 245533721 in words is "two hundred forty-five million, five hundred thirty-three thousand, seven hundred twenty-one".