1909951 has 2 divisors, whose sum is σ = 1909952. Its totient is φ = 1909950.

The previous prime is 1909949. The next prime is 1909981. The reversal of 1909951 is 1599091.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1909951 - 2¹ = 1909949 is a prime.

Together with 1909949, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1909981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 954975 + 954976.

It is an arithmetic number, because the mean of its divisors is an integer number (954976).

2^1909951 is an apocalyptic number.

1909951 is a deficient number, since it is larger than the sum of its proper divisors (1).

1909951 is an equidigital number, since it uses as much as digits as its factorization.

1909951 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3645, while the sum is 34.

The square root of 1909951 is about 1382.0097684170. The cubic root of 1909951 is about 124.0720834786.

The spelling of 1909951 in words is "one million, nine hundred nine thousand, nine hundred fifty-one".