691742601 has 27 divisors (see below), whose sum is σ = 1099656103. Its totient is φ = 418711920.

The previous prime is 691742593. The next prime is 691742629. The reversal of 691742601 is 106247196.

The square root of 691742601 is 26301.

It is a perfect power (a square), and thus also a powerful number.

691742601 is a `hidden beast` number, since 6 + 9 + 1 + 7 + 42 + 601 = 666.

691742601 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 335439225 + 356303376 = 18315^2 + 18876^2 .

It is not a de Polignac number, because 691742601 - 2³ = 691742593 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (691742651) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 867535 + ... + 868331.

Almost surely, 2^691742601 is an apocalyptic number.

691742601 is the 26301-st square number.

691742601 is the 13151-st centered octagonal number.

It is an amenable number.

691742601 is a deficient number, since it is larger than the sum of its proper divisors (407913502).

691742601 is an equidigital number, since it uses as much as digits as its factorization.

691742601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1622 (or 811 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The cubic root of 691742601 is about 884.3988601753.

Multiplying 691742601 by its sum of digits (36), we get a square (24902733636 = 157806²).

Adding to 691742601 its reverse (106247196), we get a palindrome (797989797).

The spelling of 691742601 in words is "six hundred ninety-one million, seven hundred forty-two thousand, six hundred one".