253608781 has 6 divisors (see below), whose sum is σ = 257892782. Its totient is φ = 249328920.

The previous prime is 253608769. The next prime is 253608809. The reversal of 253608781 is 187806352.

It can be written as a sum of positive squares in only one way, i.e., 149670756 + 103938025 = 12234^2 + 10195^2 .

It is not a de Polignac number, because 253608781 - 2⁵ = 253608749 is a prime.

It is a super-2 number, since 2×253608781² = 128634827600611922, 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 (253608701) 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, 123360 + ... + 125398.

Almost surely, 2^253608781 is an apocalyptic number.

It is an amenable number.

253608781 is a deficient number, since it is larger than the sum of its proper divisors (4284001).

253608781 is an frugal number, since it uses more digits than its factorization.

253608781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4139 (or 2100 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 40.

The square root of 253608781 is about 15925.0990891737. The cubic root of 253608781 is about 632.9772417149.

The spelling of 253608781 in words is "two hundred fifty-three million, six hundred eight thousand, seven hundred eighty-one".