690390787 has 2 divisors, whose sum is σ = 690390788. Its totient is φ = 690390786.

The previous prime is 690390781. The next prime is 690390817. The reversal of 690390787 is 787093096.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 690390787 - 2¹¹ = 690388739 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 690390787.

It is not a weakly prime, because it can be changed into another prime (690390781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 345195393 + 345195394.

It is an arithmetic number, because the mean of its divisors is an integer number (345195394).

Almost surely, 2^690390787 is an apocalyptic number.

690390787 is a deficient number, since it is larger than the sum of its proper divisors (1).

690390787 is an equidigital number, since it uses as much as digits as its factorization.

690390787 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 571536, while the sum is 49.

The square root of 690390787 is about 26275.2885236300. The cubic root of 690390787 is about 883.8223825527.

The spelling of 690390787 in words is "six hundred ninety million, three hundred ninety thousand, seven hundred eighty-seven".