245531681 has 4 divisors (see below), whose sum is σ = 245609364. Its totient is φ = 245454000.

The previous prime is 245531651. The next prime is 245531683. The reversal of 245531681 is 186135542.

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

It can be written as a sum of positive squares in 2 ways, for example, as 80640400 + 164891281 = 8980^2 + 12841^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-245531681 is a prime.

It is a super-2 number, since 2×245531681² = 120571612749371522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (245531683) 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, 33890 + ... + 40491.

It is an arithmetic number, because the mean of its divisors is an integer number (61402341).

Almost surely, 2^245531681 is an apocalyptic number.

It is an amenable number.

245531681 is a deficient number, since it is larger than the sum of its proper divisors (77683).

245531681 is an equidigital number, since it uses as much as digits as its factorization.

245531681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77682.

The product of its digits is 28800, while the sum is 35.

The square root of 245531681 is about 15669.4505647135. The cubic root of 245531681 is about 626.1847870815.

The spelling of 245531681 in words is "two hundred forty-five million, five hundred thirty-one thousand, six hundred eighty-one".