690561181 has 2 divisors, whose sum is σ = 690561182. Its totient is φ = 690561180.

The previous prime is 690561167. The next prime is 690561187. The reversal of 690561181 is 181165096.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 489913956 + 200647225 = 22134^2 + 14165^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-690561181 is a prime.

It is a super-2 number, since 2×690561181² = 953749489408229522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 690561181.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (690561187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345280590 + 345280591.

It is an arithmetic number, because the mean of its divisors is an integer number (345280591).

Almost surely, 2^690561181 is an apocalyptic number.

It is an amenable number.

690561181 is a deficient number, since it is larger than the sum of its proper divisors (1).

690561181 is an equidigital number, since it uses as much as digits as its factorization.

690561181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12960, while the sum is 37.

The square root of 690561181 is about 26278.5307998754. The cubic root of 690561181 is about 883.8950880629.

It can be divided in two parts, 6905 and 61181, that added together give a palindrome (68086).

The spelling of 690561181 in words is "six hundred ninety million, five hundred sixty-one thousand, one hundred eighty-one".