691650437 has 2 divisors, whose sum is σ = 691650438. Its totient is φ = 691650436.

The previous prime is 691650419. The next prime is 691650467. The reversal of 691650437 is 734056196.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 599221441 + 92428996 = 24479^2 + 9614^2 .

It is a cyclic number.

It is not a de Polignac number, because 691650437 - 2¹⁸ = 691388293 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 691650394 and 691650403.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (691650467) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345825218 + 345825219.

It is an arithmetic number, because the mean of its divisors is an integer number (345825219).

Almost surely, 2^691650437 is an apocalyptic number.

It is an amenable number.

691650437 is a deficient number, since it is larger than the sum of its proper divisors (1).

691650437 is an equidigital number, since it uses as much as digits as its factorization.

691650437 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 136080, while the sum is 41.

The square root of 691650437 is about 26299.2478409555. The cubic root of 691650437 is about 884.3595809421.

The spelling of 691650437 in words is "six hundred ninety-one million, six hundred fifty thousand, four hundred thirty-seven".