1904955669781 has 2 divisors, whose sum is σ = 1904955669782. Its totient is φ = 1904955669780.

The previous prime is 1904955669779. The next prime is 1904955669797. The reversal of 1904955669781 is 1879665594091.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1147542282756 + 757413387025 = 1071234^2 + 870295^2 .

It is a cyclic number.

It is not a de Polignac number, because 1904955669781 - 2¹ = 1904955669779 is a prime.

It is a super-2 number, since 2×1904955669781² (a number of 25 digits) contains 22 as substring.

Together with 1904955669779, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 1904955669781.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1904955669481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 952477834890 + 952477834891.

It is an arithmetic number, because the mean of its divisors is an integer number (952477834891).

Almost surely, 2^{1904955669781} is an apocalyptic number.

It is an amenable number.

1904955669781 is a deficient number, since it is larger than the sum of its proper divisors (1).

1904955669781 is an equidigital number, since it uses as much as digits as its factorization.

1904955669781 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 146966400, while the sum is 70.

The spelling of 1904955669781 in words is "one trillion, nine hundred four billion, nine hundred fifty-five million, six hundred sixty-nine thousand, seven hundred eighty-one".