690298621 has 2 divisors, whose sum is σ = 690298622. Its totient is φ = 690298620.

The previous prime is 690298613. The next prime is 690298649. The reversal of 690298621 is 126892096.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 438441721 + 251856900 = 20939^2 + 15870^2 .

It is a cyclic number.

It is not a de Polignac number, because 690298621 - 2³ = 690298613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (690298691) 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, 345149310 + 345149311.

It is an arithmetic number, because the mean of its divisors is an integer number (345149311).

Almost surely, 2^690298621 is an apocalyptic number.

It is an amenable number.

690298621 is a deficient number, since it is larger than the sum of its proper divisors (1).

690298621 is an equidigital number, since it uses as much as digits as its factorization.

690298621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 93312, while the sum is 43.

The square root of 690298621 is about 26273.5346118485. The cubic root of 690298621 is about 883.7830512057.

The spelling of 690298621 in words is "six hundred ninety million, two hundred ninety-eight thousand, six hundred twenty-one".