690894181 has 2 divisors, whose sum is σ = 690894182. Its totient is φ = 690894180.

The previous prime is 690894143. The next prime is 690894203. The reversal of 690894181 is 181498096.

690894181 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 642369025 + 48525156 = 25345^2 + 6966^2 .

It is a cyclic number.

It is not a de Polignac number, because 690894181 - 2⁷ = 690894053 is a prime.

It is a super-2 number, since 2×690894181² = 954669538679321522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (690894101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345447090 + 345447091.

It is an arithmetic number, because the mean of its divisors is an integer number (345447091).

Almost surely, 2^690894181 is an apocalyptic number.

It is an amenable number.

690894181 is a deficient number, since it is larger than the sum of its proper divisors (1).

690894181 is an equidigital number, since it uses as much as digits as its factorization.

690894181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 124416, while the sum is 46.

The square root of 690894181 is about 26284.8660068869. The cubic root of 690894181 is about 884.0371414989.

The spelling of 690894181 in words is "six hundred ninety million, eight hundred ninety-four thousand, one hundred eighty-one".