245551 has 6 divisors (see below), whose sum is σ = 256352. Its totient is φ = 234960.

The previous prime is 245533. The next prime is 245561. The reversal of 245551 is 155542.

It is not a de Polignac number, because 245551 - 2⁵ = 245519 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (245501) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2715 + ... + 2803.

2²⁴⁵⁵⁵¹ is an apocalyptic number.

245551 is a deficient number, since it is larger than the sum of its proper divisors (10801).

245551 is an frugal number, since it uses more digits than its factorization.

245551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 209 (or 120 counting only the distinct ones).

The product of its digits is 1000, while the sum is 22.

The square root of 245551 is about 495.5310282919. The cubic root of 245551 is about 62.6201209873.

Subtracting from 245551 its reverse (155542), we obtain a palindrome (90009).

The spelling of 245551 in words is "two hundred forty-five thousand, five hundred fifty-one".