508778161 has 2 divisors, whose sum is σ = 508778162. Its totient is φ = 508778160.

The previous prime is 508778087. The next prime is 508778173. The reversal of 508778161 is 161877805.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 480486400 + 28291761 = 21920^2 + 5319^2 .

It is a cyclic number.

It is not a de Polignac number, because 508778161 - 2¹³ = 508769969 is a prime.

It is a super-2 number, since 2×508778161² = 517710434221083842, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (508778461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 254389080 + 254389081.

It is an arithmetic number, because the mean of its divisors is an integer number (254389081).

Almost surely, 2^508778161 is an apocalyptic number.

It is an amenable number.

508778161 is a deficient number, since it is larger than the sum of its proper divisors (1).

508778161 is an equidigital number, since it uses as much as digits as its factorization.

508778161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 94080, while the sum is 43.

The square root of 508778161 is about 22556.1113891557. Note that the first 3 decimals coincide. The cubic root of 508778161 is about 798.3184267198.

The spelling of 508778161 in words is "five hundred eight million, seven hundred seventy-eight thousand, one hundred sixty-one".