699437021 has 2 divisors, whose sum is σ = 699437022. Its totient is φ = 699437020.

The previous prime is 699437003. The next prime is 699437077. The reversal of 699437021 is 120734996.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 689640121 + 9796900 = 26261^2 + 3130^2 .

It is a cyclic number.

It is not a de Polignac number, because 699437021 - 2¹⁸ = 699174877 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 699437021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (699436021) 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, 349718510 + 349718511.

It is an arithmetic number, because the mean of its divisors is an integer number (349718511).

Almost surely, 2^699437021 is an apocalyptic number.

It is an amenable number.

699437021 is a deficient number, since it is larger than the sum of its proper divisors (1).

699437021 is an equidigital number, since it uses as much as digits as its factorization.

699437021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 81648, while the sum is 41.

The square root of 699437021 is about 26446.8716675527. The cubic root of 699437021 is about 887.6659039450.

The spelling of 699437021 in words is "six hundred ninety-nine million, four hundred thirty-seven thousand, twenty-one".