1690661899 has 2 divisors, whose sum is σ = 1690661900. Its totient is φ = 1690661898.

The previous prime is 1690661891. The next prime is 1690661977. The reversal of 1690661899 is 9981660961.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1690661899 - 2³ = 1690661891 is a prime.

It is not a weakly prime, because it can be changed into another prime (1690661891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 845330949 + 845330950.

It is an arithmetic number, because the mean of its divisors is an integer number (845330950).

Almost surely, 2^1690661899 is an apocalyptic number.

1690661899 is a deficient number, since it is larger than the sum of its proper divisors (1).

1690661899 is an equidigital number, since it uses as much as digits as its factorization.

1690661899 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1259712, while the sum is 55.

The square root of 1690661899 is about 41117.6592110981. The cubic root of 1690661899 is about 1191.2939104875.

The spelling of 1690661899 in words is "one billion, six hundred ninety million, six hundred sixty-one thousand, eight hundred ninety-nine".